# Yi Technology -- Yi-M1



## VidThreeNorth

I have been using a Yi-M1 since around the second week of August 2017.  I received it with the "1.0.20 International" firmware.  Originally I intended to use it with that firmware first and then upgrade to the April version "2.0 International" firmware, but I saw that one of the upgrades was for SD-Card compatibility and I felt that I wanted the safest firmware available for storage since a trashed card could mean losing a day's efforts.  Actually, since I had not heard of a problem with storage up till now, I think testing "1.0.20" would probably have been safe enough, but I went ahead with the upgrade.

I will not be attempting anything like a "full review" of this camera.  I will only report specific issues that I am interested in or specific problems I run into.


*Full Reviews are at:*

"New kid on the block: YI M1 review"
Published Nov 29, 2016 | Chris M Williams
"New kid on the block: YI M1 review"
_My Notes:
According to the publishing date this review was written before version "1.0.20 International" which was the first reasonably stable firmware.  There is no indication of an update, so it is best to read this as "historical".
[Added 2016-09-10]_

"YI M1 Review", "Camera Reviews / YI Cameras"
"YI M1 Review: Now Shooting!"
Last update "07/31/17: Field Test Part II"
by "Mike Tomkins"

My Notes:
While Tomkins does not state outright which the last firmware he used was, it was clearly the version "2.0 International" (he mentions "mid-April").  Apparently his camera is having "locking up" problems.  I have not experienced any yet.  I also noticed that his camera was made in China.  Mine was made in Indonesia.

"PCMag.com"
"Reviews/Consumer Electronics/Digital Cameras/YI M1"
"By Jim Fisher, December 2, 2016 12:20PM EST"
"YI M1"

My Notes:
The firmware is not identified, but I suspect that it was at best 1.0.20 International, and possibly earlier.  This review has the most useful lens analysis  Apparently the lenses are both quite good optically.  It would be nice if they re-tested it with newer firmware, in particular the auto-focus speed and image quality might have improved.


*Firmware 2.0 Changes:*

The 2.0 firmware has a new icon on the right side of the screen which opens a menu for selecting the function of the far right "wheel" control.  It can redefine the wheel to adjust "Focus Mode", "ISO", "White Balance", "Metering Mode", "File Format" (RAW or JPEG) or "Drive Mode".  This adds a second level of quick adjustments to the three dedicated screen buttons on the left which force control of "F-Stop", "Shutter Speed" or  "Exposure Compensation" and the "Quick" hardware button on the bottom right outside the screen and the rotary Mode control on the top deck.
_[2017-08-26 replaced "while" with "wheel"]_

If I had tested the 1.0.20 firmware I could say for certain how much difference having this new icon with is new set of controls changes the usability of the camera, but it seems likely to me that it is a substantial improvement for users.

Another change that I know has occurred is that zooming during 4K video does not seem to cause exposure errors as it did in the past.  Apparently this was partly the fault of the metering forcing the aperture fully open.  I have no current easy way to test whether it still forces the aperture fully open, but I do not think so.

When the first reports came out about the exposure "flashing" when the zoom was used, I thought that it could be a problem of the processor being over-used, and that it might be best to reduce the frame rate from 30 fps down to 24 fps.  But not only has this problem been addressed without reducing the framerate, but I did not notice the camera body becoming unusually hot.  So while the processor is probably being heavily utilized, it does not seem to be pushed as hard as some other early or low end 4K video cameras (such as the Panasonic GX850 and the Sony a6300).

"Full HD" video now supports stabilization.  I have not tried it yet.


*About the 4K video Sensor Crop*

The Yi-M1 is not the only camera cropping the sensor during 4K video recording, but the amount of cropping is more than the other Micro 4:3 cameras ("budget" Panasonics).  The Panasonics start with a 16M sensor and crop that down to the 3840 x 2160 "4K" video format.  In the X dimension this is a crop from about 4592 sensors (the DC-GX850 16 GB largest still picture format is 4592 x 3448) down to 3840 pixels for 4K video for a lens equivalence ratio of about 1.2X (compared to the full Micro 4:3 sensor usage).  The Yi-M1 based on a 20MP sensor with X dimension of about 5184 sensors (based on the 5184 x 3888 20MP image format) and crops it to 3840 for 4K for a lens equivalence ratio of about 1.4X which is close to the same reduction from a full size APS sensor down to APS-C (which is roughly 1.5X).  All the issues for that degree of sensor cropping apply equally in this situation as the do for using APS-C cropping modes on full frame cameras such as the various Canons, Nikons and Sonys.  The importance to me is that the reduction in effective resolution is a significant issue for both the lower end Panasonics, but even worse for the Yi-M1.  Personally, I think the reduction in effective sharpness is generally ignorable in the Panasonics, but for the Yi-M1, I will be paying attention to lens selection.  In general, I will probably want to stay more with my sharper lenses on the Yi-M1.

Calculating the sensor crop factor compared to a APS Full Frame, the Micro 4:3 sensor is 17.30 mm wide.

_Start by calculating the effective width of the Yi-M1 sensor while recording 4K video. [added 2017-09-10]_
17.30 mm * (3840 / 5184)
= 17.30 mm * 0.74074
= 12.8 mm

So, for the 4K video mode, the actually used sensor area has a 35mm camera equivalence ratio of 36mm / 12.8mm ~ 2.8, which is close to a 1" (CX) sensor.  A 50mm lens will give the view of a 140mm lens on a 35mm camera.


*Confirming my Sensor Usage Estimate (above):*

Back to the brick walls.  I set the Yi-M1 on a tripod and pointed it at a handy brick wall (at an approximate distance of about 10') and used the Yi 42.5mm lens for this series of tests.  All focussing and exposure was set to automatic.  The lighting changed due to cloud movement.

Pic01 is a 20MP still image reduced to 1640 pixels wide.
Pic02 is a 4K frame capture reducted to 1640 pixels wide.
Pic03 is a center (full resolution detail) crop of Pic01 (1640 x 1230)
Pic04 is a center (full resolution detail) crop of Pic02 (1640 x 1230)
_[2017-08-26 NOTE:  The 20MP still image was a RAW converted in Corel Paintshop Pro X7.  I have not been using the built in JPEG yet.]_

Aside from a small vertical discrepancy probably caused by my touching the camera, the center crops cover almost identical views.

Partial EXIF data from the 20MP still:
Exposure program Aperture priority, Scene capture type Standard
Exposure mode Auto, 1/100 sec., f/5.6, ISO 1250,
Metering mode Center weighted average, Gain control "High gain up"

Video settings unknown except No Exposure compensation used.
Everything "default".

[To Be Continued -- someday, but probably not very soon. ]


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## fmw

It is an interesting niche to inhabit - the interchangeable lens point-and-shoot.  I think it may do reasonably well in the marketplace thanks to its $400 price.  Serious photographers, though, are likely to prefer cameras with more control - things like manual focus.


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## VidThreeNorth

fmw said:


> It is an interesting niche to inhabit - the interchangeable lens point-and-shoot.  I think it may do reasonably well in the marketplace thanks to its $400 price.



Your pricing is off.  At B&H it cost $300 US for the silver body with the zoom lens.  The price for the black body and with both the zoom and the 42.5mm 1.8 lens it is $380 US.  I bought the 2 lens package.  These prices are closer to stock GoPro Hero5 range.



fmw said:


> Serious photographers, though, are likely to prefer cameras with more control - things like manual focus.



The Yi-M1 has manual focussing for still photography including screen magnification and "peaking" for assistance.  I have not tried it much but it seems to be working.  Apparently it did not have manual focussing for video in version 1.x firmware.  I have not been looking for it in version 2.0 yet.  It was not mentioned in the changes list, but sometimes changes are not documented in this industry.

Beyond that, it is still too early for me to have a real opinion about the camera overall.  My first 4K video test was made with a Panasonic 12-32mm zoom lens because I did not know what quality the Yi lenses had.  So my first 4K video looked quite good.  I have a bit more confidence in the Yi lenses now.  The 42.5mm is very good.  The PCMag report numbers for the zoom show that it is "ok".  I have another 4K video made with that lens but I have not really looked at it yet.


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## fmw

The lenses do not have focusing rings.  What you call manual focusing is simply manipulating the motorized AF system with the touch screen.  I took the prices from Amazon.  Sounds like it is a better deal than I thought.  Post some images when you can.


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## VidThreeNorth

*About the Lenses:*

First, I wanted to post a clarification about my comment about the Yi zoom.  Optically, from the test numbers it looks mediocre.  There is no better way to put it.  But if you look at the closest similar lenses from Olympus and Panasonic, their basic numbers are no better.  It seems to be common characteristic of "cheap kit zooms".  I expect that if I looked at the numbers for Canon, Nikon and Sony they would be similar.  But on the Yi-M1, as I noted above, if I want to record 4K video, this lack of "stellar quality" is going to show up, and it will be a bit worse than in the low end Panasonics (GX-850 and GX-85).  If I want to make a general rule, actually, if I use the Yi-M1 for 4K video, I think it would be worth it to stick with "prime lenses".

@fmw:

Yi only has 2 lenses.  As you say, the 42.5mm has no focus control ring, but the zoom has a focus control ring.  It works the same as most of the latest auto-focus camera lenses.  You turn the ring and it causes the focusing motor to make the adjustment.  The Yi 42.5mm lens is not the only Micro 4:3 lens to not have a focus control ring.  My Panasonic 12-32mm zoom is also missing the focus ring, and there may be others too.  On some of the cameras, like my Panasonic GF3, there really is _no _way to manually focus the lens _[not even for still picture -- clarification added 2017-09-10]_.  But I expect that the modern Panasonic and Olympus camera bodies have some kind of focus control on the body.  I have never tried any of those cameras except the ones I bought, so I do not know.  Now that I know the camera is working, I "packed it away".  I have too much other stuff to get done right now.  This is why I said in the first message that I will not be adding to this topic for a while.  Besides, just as a reference for the potential image quality, there are plenty of test pics available in the reviews I linked above.  I posted the "wall" pictures because I had something to say that has not been covered in any of the reviews.  Nobody seemed to want to "do the math".  I don't blame them really. . . .


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## fmw

I think it will find a pretty good market in the U.S.


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## VidThreeNorth

As I wrote before, I have not had a lot of time to look at the Yi-M1 and there has been a general range of issues that I needed to settle.  Mostly, they have to do with focussing.

On Aug. 13, I took the Yi-M1 to the "Taste of the Danforth" street festival in the east side of Toronto.  I was only there briefly.  I recorded a few video clips in 4K and 2K, and took a few pictures.

Everything was done using the kit zoom (12-40mm, F3.5-5.6).  The camera was on a monopod above my eye level.  Without a tilt screen this was difficult to use.  Because there is no stabilization for the 2K and 4K video modes, I had to think about composing with later stabilization in mind.  In general, I left more at the top of the frames than I usually would.  At the bottom of the frames, I thought the speakers would cut off their feet anyway, so I left them close to the bottom of the frame.  In retrospect, I think I should have zoomed back a bit and framed a bit lower, including the feet and below.  Both clips looked in focus in the screen while I was recording.

If I had been located in front of the stage the scene would have been badly backlighted because there was no back to the stage, which was where the sun was.  I generally prefer to work from an angle anyway, but in this case I used a specific angle which put the side of the stage as the background, reducing the backlighting problem.  Exposure for the first clip was EV = +1.  At some point I changed the exposure to EV = + 1.3.  It might have been between the 2 clips or after the second clip.  I did not make a note about it, but I found out later in the day that it was set at EV = +1.3, and I do not know if I did this deliberately or by accident.  I do think it was deliberate and probably before the 2K clip which seems to be higher exposed, but this might be due to the change in composition with the 4:3 framing.  The "Yi-M1" does not allow changes in the exposure compensation during video recording.
_[2017-09-24 grammatical corrections.]_

_Additionally, I set my metering to "Center Weighted".  I usually use this method on all my cameras for video and still images because it is generally consistent from camera to camera.  It is not necessarily a "better" practice, it is just what I am accustomed to.

Also, I should mention that the Yi-M1 exposure compensation allows +/- 5.0 EV, which is very wide.
[Added 2017-09-10]_

When I finally got to review the clips on a computer, I noticed that in the 4K clip, the singer (blue dress) seemed out of focus.  I did some frame captures and confirmed it.  While the depth of field was very deep, I could tell that the auto-focus had picked the store faces on the street _[in the background -- added 2017-09-10]_ to focus on rather than the performers.  As far as I am concerned, this clip is not acceptable.

On the other hand, the 2K clip focussed on the performers as I had wanted.  This clip is usable, and in fact, overall, I like it.  The sound is not wonderful, but then again, it was not that good coming from the stage.


*Other problems:*

I cannot use a "very slow zoom" on this lens.  This is very annoying because it is a technique I used often.  On my Sony CX240B camcorder in particular, I can zoom so slowly many people will not even notice that I am zooming.  The Canon R40 can slow zoom too, but the control is a bit harder to use.  When I tried to "slow zoom" the Yi "12-40" the zoom ring would stick and it caused a series of small jumps ("judder").  If I grip the zoom ring harder to try to get it to move, then the problem gets worse.  The zoom ring is too flexible and it is the friction of the zoom ring against the lens barrel that is causing the sticking.  The design and the choice of materials are the cause of the problem, and it is unlikely to improve with use -- it is not going to "wear in".


*Back to Focussing:*

During 4K recording there does not seem to be a way to "fine tune" the _[automatic]_ focusing system.  I tried the "face detect" but it seems to be disabled.  The "face detect" box did not appear.  The "touch focus" using the touch screen is also disabled.  So whatever way the normal auto-focus works is what is happening.  I think that the reason it did well with the 2K might have been because of the 4:3 format.  There was simply less of the extra background in the composition to confuse the auto-focus.  In that case, I think I am going to like using the 2K video a lot more.
_[edited 2017-09-10 clarification]_


*Video Manual Focus Works BUT:*
_[Edited subtitle 2017-09-10]_

One thing I checked later is that for video, the manual focus systems PARTIALLY work.  Here is the situation for 4K and 2K recording.  The other video modes are probably the same, but I have not tested them:

IF you have a _[Micro 4:3 auto-focus lens with a]_ focus ring on the lens,
THEN you can select manual focussing BEFORE you start recording.  You can chose "Manual" or "Manual w/Peaking".  _Once recording has started, this mode cannot be changed until the recording has stopped.  [Clarified 2017-09-10]_
- The display magnification  does NOT work during these video modes.

IF the lens does NOT had a focus ring (like the 42.5mm prime lens)
THEN whatever setting you have selected for focussing will be ignored during video recording and it will use "Continuous Auto-Focus".

IF you are using an ADAPTED lens (or any other lens that does not have the electronics for auto-focus),
THEN you can select "Manual" focus or "Manual focus w/Peaking".  On adapted lenses, you might also be able to adjust the aperture manually (depending on the lens and the adapter), and thus have depth of field control as well.  _But again, the Screen Magnification will not work during recording. [Clarification added 2017-09-10]_


*Still Not Tested:*

I have not tested the colour temperature selection or "Scene" modes yet.


*Best Approach:*

If I am going to do "critical 4K video work", well first, I would probably not even use the Yi-M1 if it was _that_ important, but if I do use it, then the best approach would be put the camera on a tripod and use a lens with a focus ring.  I would set the focus to "Manual" and then use the magnifier to check the focus before starting the recording, and if possible, LOCK the focus and start the recording.  I would avoid trying "focus pulling" because during the video recording I would not have the view magnifier available to check the re-focussing.
_[Slight reformatting 2017-09-10]_

Really, I think I might use the "2K" video mode quite a bit.  The lack of excess background seems to help the focus work well enough, and on YouTube I think a lot of people will like the format.


*About Video Formats:*

The "2K" video format is a "GoPro" format and as such is it not new.  I was surprised that they did not include another "intermediate" format.  2560 x 1440p is _[a format that is]_ available in a lot of the Action Cameras.  I like using it on the Git2.  _I was surprised that this format was *not* included on the Yi-M1. [Clarification 2017-09-10]
*
Further Corrections:*
GoPro Hero5 Black 4:3 resolution formats are:

- 2.7K 4:3 @30/25 fps 2704x2028
- 1440p 4:3 @30/25 and 24/24 1920x1440

As far as I know, the 2048 x 1536 format was first used by Yi.

In the long run, this will not make a difference since video editors will handle the re-sizing (although I have some concern whether Pinnacle will allow outputting to any of these large 4:3 sizes).  The 1440p 4:3 was the actual size that I was thinking about when I called the "2K" format a "GoPro format".  The Yi "2K" format would resize downward to the 1440p 4:3 format nicely, including post-production stabilization.
[Above added 2017-09-12]_

*Pixel Counts:*

3840 x 2160 = 8,294,400

2560 x 1440 = 3,686,400 _[This format is not on Yi-M1]
[Clarification added 2017-09-10]_

2048 x 1536 = 3,145,728

1920 x 1080 = 2,073,600

1280 x 720 = 921,600

_If Yi were t0 add a 2560 x 1440 resolution mode it might be possible to use the full width of the sensor which would make better use of the lenses than the current 4K mode.
[2017-09-24 Added above paragraph.]_

The 2560 x 1440 format is a 16:9 format which scales nicely both up to "4K" and down to "Full HD".   The processing power needed for its support is only a bit more than the "2K" format and likewise the file sizes are only a bit bigger.

I do not know whether there might be problems with processing power if the 4K video is "enhanced" with future firmware changes, but both 2K and "2560" formats should leave enough processor "head room" for such firmware changes in the future.

Also, both "2K" and "4K" video formats are currently only available in 30 fps.  Providing 24 fps (a "Pro" video speed) would also be appreciated.


*Another Recommended Firmware Change:*

I think that one firmware change I can recommend would be to provide a "narrow zone" auto-focus option for video.  I would limit the focus to about the inner 1/2 of the frame and put a box of some kind indicating it.  Either that or I would try to enable the "touch focus" system for video.


*Aperture Working during 2K and 4K Video:*
_
On a later test I confirmed that the aperture is not locked fully open during 2K and 4K video recording, which was mentioned in some of the reports prior to firmware 2.0 International.
[Added 2017-09-10]_


*About the uploads:*

The "detail" files are full resolution.


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## VidThreeNorth

*Two Issues that I will Eventually Get Around Too:*

I will eventually get around to checking the "bit-rates" for 2K and 4K video.  I am not that concerned with them.  Visibly, they look pretty good.

I _am_ concerned about how the controls work in cold weather.  A few years ago I found that my LG cellphone' s touch screen would become unresponsive in cold weather.  The temperatures below freezing were a problem.  I do not know exactly how cold it was when the problems started.  I remember a couple of times when I was using the cell phone camera for short videos and I could not stop the app.  I had to pull out the battery.  If the touch screen on the Yi-M1 fails in cold weather, then this camera can only be used indoors and in "fair weather".  Even if this turns out to be a problem, I _can_ find good use for the camera, but many people could end up very upset if this is a problem.  I will probably not get around to this issue till winter.


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## VidThreeNorth

The final version of the 2K video, which features *"Olivia and the Creepy Crawlies"* singing *"Gatsby"* is at:

"20170813 Gatsby_Taste of the Danforth_Toronto"
"



"

I would like to thank them for their permission to make this video available on YouTube!

Processing was Magix Movie Edit Pro 2016 Plus 64-bit on my ASUS M32BF AMD A8-6500 and Windows 8.1.  The included "proDAD Mercalli 2.0" plug-in did a particularly good job stabilizing the video, and particularly, dealing with "shutter roll" which occurred early in the video as I was "getting set up" and the zoom "judder" later in the video, caused the sticky manual control ring.

Unfortunately, a bug in the program stopped the title screen from fading out, but someday I might be able to fix that.

I do not know if Pinnacle would have allowed me to render a 2048 x 1536 output file, so for now, I might not have any other options.


*Re "2K" video format:*

GoPro Hero5 Black 4:3 resolution formats are:

- 2.7K 4:3 @30/25 fps 2704x2028
- 1440p 4:3 @30/25 and 24/24 1920x1440

As far as I know, the 2048 x 1536 format was first used by Yi.

In the long run, this will not make a difference since video editors will handle the re-sizing (although I have some concern whether Pinnacle will allow outputting to any of these large 4:3 sizes).  The 1440p 4:3 was the actual size that I was thinking about when I called the "2K" format a "GoPro format" (above).  The Yi "2K" format would resize downward to the 1440p 4:3 format nicely, including post-production stabilization.

_I tested the "2K" video format when I make the "brick wall" recordings and it uses the full sensor array.  The captures I made showed the same coverage as the 20MP still picture.  This also means that it uses the Micro 4:3 lenses fully, so there is no need for any special considerations about lens performance or angle of coverage.
[Added 2017-09-24]_


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## VidThreeNorth

*Bit Rate for Yi "2K" video mode:*

I would prefer to wait until I have a few video clips to take stats from  but lately I have been using my camcorders for video work, so I have not accumulated video files taken on the Yi-M1 yet.  But the "Olivia and the Creepy Crawlies" video has been made available, so at the very least if I take the stats from the camera file for that video, you can at least have some idea of how well this video mode works.

These are the stats that I got for the original camera file from the VLC media player and the Window 8.1 OS:

VLC stats:

Stream 0
Codec: H264 - MPEG-4 AVC (part 10)(avc1)
Language English
Resolution 2048x1538
Display resolution: 2048x1536
Frame rate: 29.970029
Decoded format Planar 4:2:0 YUV full scale
Stream 1
Type Audio
Codec MPEG AAC Audio (mp4a)
Language: English
Channels: Stereo
Sample rate: 48000 Hz


Windows 8.1 Properties (partial stats):

Size: 804 MB (843,740,520 bytes)
Created August 13, 2017, 15:51
Video:
Length: 03:44
Frame width 2048
Frame height 1536
Data rate 30002kbps
Total bitrate 30130kbps
Frame rate 29 frames/second _[Windows Properties rounds the frame rate downwards 2017-09-24]_
Audio:
Audio bit rate 127 kbps
Channels 2 (stereo)
Audio sample 48kHz

*Calculation:*

Video bit rate:
30,002 kbps /1024
~ 29.3 Mbps

Overall bit rate:
Approximate Mbps: 30130 / 1024
~ 29.4 Mbps

Confirm:
224 sec x 29.4 = 6,590,375 Mbits
6,590,375 Mbits / 8 = 823.9 MBytes
(~ 863,887,360 bytes) (a slight discrepancy, close enough)

So the target bit rate is probably ~29.5 Mbps

*Yi Website* accessed 2017-09-16 15:48

No bit rates are provided by Yi Technology in the specs in the manual nor online.


*Comparing the Yi "2K" format with good "Full HD" camcorder files:*

Yi's "2K" 2048 x 1536 = 3,145,728 pixels
"Full HD" 1920 x 1080 = 2,073,600 pixels

29.5 Mbps * (2,073,600 / 3,145,728)
~ 19.4 Mbps

Compare this to a Canon Vixia HF-R70: MP-4 files:
Full HD 1920 x 1080 @ 30 fps
- High Quality = 24 Mbps,
- Standard Quality = 17 Mbps

So, on a "per pixel" basis, the Yi records its "2K" video at a better data rate than a Canon R70's "standard" "Full HD" quality, but not by a lot.

Or looking at it on a "per frame" basis, it is 100 x 29.5 / 24
~ 23% better quality than Canon R70's High Quality 30 fps "Full HD" frames.

Considering that the Canon Vixia HF-R70 is a well respected consumer camcorder the numbers are very good.  It is no surprise that the YouTube uploaded final file looks as good as it does.


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## VidThreeNorth

*"4K" Video Bit Rate Calculation:*

*About the Test Clip:*

"P8120005.MP4" [Recorded 2017-0812, Firmware 2.0 International]
- I will not be posting this clip anywhere.  It is nothing more than some panning and some zooming.  The sample capture shows about all there is to see really.

As I wrote above, I had not intended to try calculating bit rates until I had a variety of clips from which I could chose.  But then I decided to post calculations based on the "2K" clip that was the basis for the "Olivia and the Creepy Crawlies" performance video, and since I had done that much, I looked through my "4K" clips to see if I had one that might give sufficient stats that I could post. I also decided to check further and see if any of the previous reviews had stats.  When I checked their Yi Technology's English website I did not find any, but it is possible that they have published them somewhere else where I would have missed it.  Or an astute writer could have asked the question to Yi and the information provided directly to them.  I found such a list in dpreview.com's:

According to the "DPreview.com" stats page for the Yi-M1, the video bitrates (with an early firmware, possibly pre- "1.0.20 International") were as follows:

"3840 x 2160 @ 30p / 75 Mbps, MOV, H.264, AAC
1920 x 1080 @ 60p / 30 Mbps, MOV, H.264, AAC
1920 x 1080 @ 30p / 15 Mbps, MOV, H.264, AAC
1920 x 1080 @ 24p / 15 Mbps, MOV, H.264, AAC
1280 x 720 @ 60p / 15 Mbps, MOV, H.264, AAC
1280 x 720 @ 30p / 10 Mbps, MOV, H.264, AAC
1280 x 720 @ 24p / 10 Mbps, MOV, H.264, AAC"

See: "https://www.dpreview.com/reviews/yi-m1/2"
- accessed 2017-09-19 14:57

Looking at the above table, the first thing to note is that there is no "2K" bit rate.  I assume that this is because the "2K" video format was added later.  So this calculation will be aimed at verifying the "4K" bit rate (75 Mbps).


The test clip was one of my first on this camera.  At the time, I did not know if the Yi lenses were good or not (it turns out that the lenses were both respectable, particularly the 42.5mm) so I used my Panasonic H-FS12032 (12-32mm, F3.5-5.6 manual zoom) lens.  This lens is widely owned.  Most owners of Panasonic Micro 4:3 cameras have this lens, so it is a good reference.  A prime lens would be a bit sharper, but I did not have access to my 14mm lens.  Exposure is compensated (EV = +2.0) for shadow detail, but is still within range to maintain cloud detail.

This particular video clip tested panning and zooming.  It was mainly recorded at 32mm but I zoomed all the way to 12 and back to 32.  It lost focus for a while zooming _in [toward telephoto -- corrected 2017-09-24]_, but got it back fairly quickly.  The +2 exposure was intended to pickup shadow detail but, as mentioned, without losing the clouds.  Because this clip used a lot of zooming and panning, it might not be the sharpest throughout, but then again, it is probably representative of what can typically be expected.  Focus is automatic, so panning and zooming probably resulted in "hunting" throughout, but it only "lost focus" obviously once during the "zoom-in" test, and focus was re-acquired quickly after the zoom ended.


*VLC Codec Info:*
Stream 0
Type: Video
Codec: H264 - MPEG-4 AVC (part 10)(avc1)
Language English
Resolution 3840x2160
Frame rate: 29.970029
Decoded format: Planar 4:2:0 YUV full scale
Stream 1
Type: Audio
Codec: MPEG AAC Audio (mp4a)
Language: English
Channels: Stereo
Sample rate: 48000 Hz

*Win 8.1 Properties (partial)*
1.32 GB (1,418,384,200 bytes)
Video
Length 02:29
Frame width 3840
Frame height 2160
Data rate 76023 kbps
Total bit rate 76151 kbps
Audio
Bit rate 127 kbps
Channels 2 (stereo)
Audio sample rate 48 kHz.

*Calculations:*
Video bitrate 76023 kbps / 1024 ~ 74.2 Mbps
Total bitrate = 76151 kbps / 1024 ~ 74.4 Mbps

The 74.4 Mbps bit rate is close enough to the estimated 75 Mbps, and the overall image quality (and sound quality) are good enough to confirm that the camera is performing as well as these numbers would imply.

_I have recently recorded some 4K "stock" using the Yi zoom.  Most of it was manually focussed and showed good sharpness and detail, and yes, the bit rate for those clips are a bit higher despite high motion in the content from blowing leaves and plants.  eg. clip P9210006.MP4 Video data rate 76,955 Kbps, Total bit rate 77,084 Kbps (~75.3 Mbps).
[2017-09-24]_

The bit rate is very respectable but not earth shattering.  Yes, if you pay a lot more, say for a Panasonic GH5, you can get better results, but I do not know of anything with the Yi-M1's flexibility (ie a proper interchangeable lens system with focussing and aperture controls) within this price range that has this performance.  Also, I have to wonder whether a sharper lens might make some difference?  As I wrote earlier, lens sharpness could have a stronger effect on the Yi-M1 than on cameras with less or no sensor reduction, and while the Panasonic H-FS12032 is a very good lens compared to similar "kit zoom" lenses, a good "prime" lens would be substantially better.

Recently I have found out that the Yi-M1 "4K" video quality is probably better than the "Z-Camera E1" bit rate, which according to Videomaker, achieves about 60 Mbps, though the E1 might have other advantages I have not heard about.

Comparing this to the Canon R70 at 30 fps Full HD.  Scale the Yi "4K" bit rate down to a Full HD equivalent number (74.4 Mbps / 4) ~ 18.6 Mbps.  So this particular clip shows a bit more detail per pixel than a Canon R70 recording Full HD @ 30 fps in its "Standard Quality" 17 Mbps. and only a bit less than the 19.4 Mbps that the camera achieved on the "2K" video.  On a per frame basis, the 74.4 Mbps is still a huge increase over the Canon's "High Quality" Full HD 30 fps' 24 Mbps.


*Captured Sample Frame:*

The captured sample frame was during a pan, so the focus might be "hunting" a bit, but it looks representative of the best this setup can do.  In fact, because the depth of field is very deep, I am not sure where it is focussed.  I think it is focussed on the signal light stand, but it is very difficult to tell.

At EV = +2.0 the shadow detail was passable even without adjustments.  As noted above, the clouds were completely "within bounds" meaning no loss of detail.  While this frame (and the whole clip really) seem to allow a slight increase to around EV = +2.3, I would not want to risk it in a situation because such clouds are unpredictable.  A bright patch could clip.  Testing various alterations show that a lot of "hidden" detail has been maintained.

As usual, the "Detail" crop is full resolution.  I have also uploaded some variations.  The variation of the full frame file shows an "equalized histogram" bringing out the cloud details, and the variation of the "detail" crop is a more subtle histogram adjustment (mid-tone compression 10) which is just enough to bring out shadow details.

*"Cap01-09h23m59s387-1920.jpg"*

*"Cap01-detail-09h23m59s387-1640.jpg"*
- a full resolution detail

*"Cap01-Alt-09h23m59s387a-HistEq-1920.jpg"*
On the full frame, an "equalized" histogram brings out dramatic cloud details.

*"Cap01-detail-Alt-09h23m59s387b-MidComp-1640.jpg"*
On the detail clip, a milder Histogram Adjust, "Mid-tone compression 10" is a more subtle alteration that is enough to reclaim more shadow detail.


----------



## VidThreeNorth

I put my finding about manual focussing the Yi-M1 during video recording back on my Sept. 8 post, but if you want to see how the manual focus is done, it is demonstrated in the following video:

"Yi M1 - Manual Focus in 4K Video Recording Mode"
posted by "mygiguser" Sep 15, 2017


----------



## VidThreeNorth

I posted my first 4K video from the Yi-M1 to YouTube on Sept. 29, 2017, but I did not post a link to it "here" because I did not feel that it warranted bringing it to this forum's attention.  It was a good enough video for my purposes (to provide a record of an event related to the Invictus Games) but it was not up to a high technical standard, and furthermore, the reasons for its short-comings were not primarily due to the hardware.  It was partly circumstantial, and partly due to a poor choice on my part.  I had a backup camcorder with me (Sony CX240B) which I knew would give me a better chance for a good video, but only in Full HD, yet I decided to take the risk on the Yi-M1 anyway.  I will explain the situation a bit:

Lately my Condo management has decided to do work on the building which requires me to re-arrange everything.  And yes, I work out of my condo, so that means re-locating things I use for work, including piles of notes and references, and equipment.  So I am pressed for time and generally disrupted in everything I do and not by my choice.  I wanted to cover the Invitus Games, but I did not have the time, except for this one event -- an evening concert.  The week before I had a chance to record some Fall "stock" clips using the Yi-M1 and its kit zoom.  I used manual focus, and used it on my usual monopod.  That was the closest I came to practicing with this setup.

For this concert, I did not know the venue.  Toronto City Hall can be set up in different ways, and this time it had been divided to provide an area for "Wheelchair Tennis".  I had not seen how this was done.  But I knew I was going to arrive late, so I expected that I would be far from the stage.  So I decided to use my new Olympus "ED 40-150mm f4.0-5.6 R" manual zoom lens.  For 4K, with the 2.8x crop factor, this performs like a 112 - 420 mm zoom on a 35mm camera.  My last 4K attempt using the 12 - 40mm kit zoom for a "music concert" had turned out good except for the focus, so  it was not unreasonable to think I could do this, as long as I stayed, perhaps, below 60mm.  But this time I would be trying manual focussing.

The big issue was that I did not have time to practice with this setup before the event.  Normally, I try to practice with my setup the night before recording--_every time_.  The difference is that when a setup is new to me, I practice longer.  With a setup as new as this, I would have liked an hour to check myself out on it, and maybe some time on my backup camcorder too.  But I did not get a chance to do any of my usual practice.  I just charged my batteries, packed up my gear, planned the trip, and tried to get some sleep.

When I arrived and setup, I found that the crowd was not so bad.  The lens forced me to setup further away than I would have with the kit zoom or the Sony.  The stage was very wide, which meant I was going to have to manually focus a lot from one end of the stage to the other.  And the stage had multiple levels, so I could not lock the up-down tilt on the monopod.  In effect, it was like handheld except the camera height above ground was constant.  With time to think it over, I could have packed up the Yi-M1 and used the Sony CX240B.  But I wanted the 4K video if possible, and my last video turned out fairly well after stabilizing in post.  So I decided to give it a try.

The result was worse than I expected.  The lighting was dark.  I had expected "normal" spotlights.  That did not happen.  Also, because I was not as familiar with the camera as I thought, I mistook the "Mode" wheel for the EV control.  I turned it and the EV did not change.  What was going wrong?  Also, I could not set "manual focus with peaking".  I could only set "manual focus".  Two or three songs into the show I looked at the camera and realized what I had done.  I had turned the Mode wheel, eventually to Panorama instead of setting the EV.  Luckily, there was no effect on the video.  Moreover, the lighting apparently did not need much EV correction.  I think EV = -0.3 would have been best, but no adjustment at all was good enough.  As for focussing without "peaking", I found it was not worse than with "peaking."  I find that the "peaking" only helps me if I have magnification, and that is never available during video recording on the Yi-M1.

But the worst thing was that without the locked tilt, and no stabilization, at that distance, the camera shake caused blurred frames that I could do nothing about in post.  Stabilizing in post does work as far as aligning the frames, but a blurred frame is still blurred.

So how much of that was due to my lack of practice the night before?  And did it make sense to use the Yi-M1 in this situation when I had the Sony CX240B ready in my camera bag anyway?

Did I learn anything?  Yes, In this situation I would not bother with the Yi-M1.  I would drop back to the Sony and bring home a better Full HD clip.  But even after I explain all this does it help anyone else?  I do not know.  All I can think is "maybe".  So I decided to post this for now, but do not be surprised if I replace this someday with a link to a better 4K video, or at least one that shows something more specific about the camera.

"[UHD] 20170926 James Blonde - Cynical - Invictus Games Concerts"
"



"


----------



## VidThreeNorth

*Olympus ED40-150mm f4.0-5.6 R MSC at UHD*

The Olympus ED40-150mm f4.0-5.6 R MSC zoom lens is a "budget" zoom lens.  I would call it a "semi-kit" zoom because it is often included in a 2 zoom kit for Olympus cameras.  This file set shows what it could do in on the Yi-M1 in this particular situation.  If you saw the video, you will know that a high percentage of the frames were out of focus or motion blurred, so it took me a bit of work to find a couple of frames that give a real idea of how good this combination could be when used "properly".  I deliberately chose frames and detail crops with the band's fans in mind, but the lens can be adequate for general use.  It is not a wonderful lens, but it is not terrible either.  In "full resolution" you will see typical YUV 4:2:0 aliasing.  The reduced "1920" images "reassemble" these anomalies to an extent.  Due to the "smoke machine" use, I advise not to assume that typical contrast is demonstrated in these frames.  Imagine how the video would have turned out if I could have held onto this quality throughout.  That is always the goal.

*"Pic01-09h36m53s437-1920.jpg"*
The black vertical mic stands in the right foreground are surprisingly sharp in both the 1920 reduced and the 1640 full resolution detail files.  I think the auto-focus would have had problems if I had used it.  If you look at this frame you see almost everything far behind the guitarist.  There are some heads in the foreground but I think maybe 70 - 80% of the frame is behind him.  My earlier experience seems to indicate that this composition would have focussed behind the guitarist.  In this frame I think I have focussed just a bit in front of him -- on the mic stands themselves.

*"Pic01a-detail-1640.jpg"*
Full resolution "detail crop of the above frame.


*"Pic02-08h59m09s086-1920.jpg"*
Ampeg, Marshall and Yamaha would be happy to see this picture.  Their logos have shown up very well.  I think that the bass is a MusicMan.  That logo was a bit too small to show up.  The drum kit and mic stands again, are good places to look for the resolution and detail.  Looking at the drum sticks, brings up the question of shutter roll.  I looked throughout the clip, and yes, I can see some shutter roll, but it did not seem bad.  I think that there is significantly more in 2K, which is understandable since the full sensor is being read.  The Panasonics have been shown to have less shutter roll than some other 4K video cameras.  I think the Yi-M1 is probably about as good.  Unfortunately, I have not made a formal test of this issue yet.

Here, the big LED stage display is a significant problem for autofocus.  The moire pattern on the screen in the "detail" file shows that the individual LED lights are almost in focus in this frame.  I have seen clips where I am certain that a camera's autofocus had gotten fooled by a big screen like this and focussed on it instead of an act in front of it.  So again, I believe that autofocus would not have worked for this clip.  But in this case it would not surprise me if some other more expensive cameras would have done poorly as well.

*"Pic02a-detail-1640.jpg"*
Full resolution "detail" crop of the above frame.


----------



## VidThreeNorth

Apparently, on Oct. 30, 2017 Yi Technology released V3.0-int firmware for the Yi-M1 camera.  I have downloaded the file and hope to complete the upload soon.  Here are the release notes:

"Version: 3.0-int
Release date: 10/30/2017
The firmware is only for the international version of  YI-M1 mirrorless camera.
It is strongly recommended that all users upgrade YI Mirrorless App to 3.0.0 to implement new features.
Firmware version 3.0-int update logs:

NEW:
1. Added exposure control in the mode P/A/S/M for video capture
2. Added AF/MF control for video capture
3. Added RAW+JPG format for still capture
4. Added still image option in Time Lapse
5. Added the option to shoot 1-3 images when using the self-timer function with an initial 2 second or 10 second timer setting
6. Added a histogram in live view mode for both still and video capture
7. Added new focus viewing modes with improved image quality including: 6x, 8x and 10x magnification in MF mode
8. Added 2 ways to show the Metering mode in the UI
9. Added the user guide (Restoring factory settings to view)
10. Added multiple selection of images for deletion.
11. Added 2 new options for the display grid
12. AE algorithm optimization
13. Master Guide template display logic optimized
14. Improved AF speed

Fixed:
Fixed some known bugs, and improved the overall stability of the system.

Changed:
Change the thumbnails in each screen from 9 to 12 images."


----------



## VidThreeNorth

I installed the Version "3.0-int" firmware last night.  I have not had time for thorough testing, and as usual I cannot even predict when I will, but I did some quick testing of issues for 4K video:

Yi 42.5mm F1.8 lens: (no focus ring)
During 4K video:
- cannot set Manual focus (no change from "version 2.0 Int.")
- EV comp is working using dial
- Touch Screen focus works during 4K video

Yi 12-40mm F3.5-5.6  zoom lens: (has a focus ring)
- Manual focus can be set and used (with or without "peaking" -- no change from "version 2.0 Int.")
- EV compensation is working using the dial
- Touch Screen focus works during 4K video

I have not tried face detect during video yet [See Below], which would also be a big asset, but this much goes very far in making the camera a viable video tool.  The "touch screen focus" is best used on a tripod or at the least, a monopod, but that is how I work for most of my video recording anyway.

_[2017-11-04]
I just ran a quick test of face detection in 4K video using the Yi 12-40mm F3.5-5.6 zoom.  It is working.  It might not be as good as some other cameras, but it definitely makes this a more useful video camera._


----------



## VidThreeNorth

*Adapting Lens To Yi-M1

Equipment Used:*
Yi-M1 (Firmware Vers "2.0-Int")
Monopod
Minolta 28mm F2.8 MD lens (Used, under $50 Cdn)
Fotodiox PRO MD - MFT" adapter MFR # MD-MFT-P (~$60 US)

I have been using adapted lenses on my Yi-M1 and my Sony a5000 lately.  The Yi-M1 attempts were aimed at use for 4K video.  My testing so far have been using a Minolta 28mm F2.8 MD (fully manual) lens for 35mm film cameras through a "Fotodiox PRO MD - MFT" adapter, but without a lens hood.

This set of files are converted from RAW and then exported without alterations (except the cropping, resizing and compressing).  In general, I was quite happy with the "PA240002.DNG" image.

*Both Source files:*
Settings: F5.6-6.3

*"PA240002_-rs1640-C5.jpg"*
PA240002 is a 20MP DNG file.  This version has been resized down to 1640 x 1230, but with more compression than I usually use (Paintshop Pro Compression level 5).    I have not provided a corner "Detail" file in this set because I plan to provide them later in actual 4K video frame captures.  But since the lens is designed as a 35mm film wide angle, one can expect that "corner" sharpness performance when used on a Micro 4:3 camera is close equaling the center, and I can report that it in fact does hold true.  The equivalent 35mm film camera view for this file would be roughly a 56mm lens.

*Partial EXIF:*
Date time: Oct 24, 2017 17:13:13
width 5200
height 3902
Pixel height 3888
Pixel width 5184
Component config YCbCr
Exposure: Normal Program
Scene capture Standard
mode: Auto exposure
bias: 0.00 ev
time 1/100
ISO 1000
Metering: Center weighted average
Gain control: High gain up

*"PA240002a-4K-1920-C5.jpg"*
This is a crop from the 20MP file representing the coverage of the camera's 4K video mode.  The actual equivalent 35mm film camera equivalent view would be roughly a 78.4mm lens.  This jump is a result of the 4K video mode using a reduced sensor area from the full M 4:3 sensor.  Again, the Paintshop Pro JPEG compression is level 5.


*"PA240002b-Detail-1200-C1.jpg"*
Lately I have tried to standardize on 1640 x 1230 pixel "Detail" crops, but for this set I found that the file sizes required too much compression.  I have reduced to 1200 x 900 in order to provide minimum JPEG image data loss.  I should caution everyone by reminding that "noise" increases file size as well as detail, and I have no way of breaking out the noise component, so while the file sizes appear impressive, do not assume it is all a result of quality.  Still, the nature of the composition does imply a fairly high detail component.


*"PA240009-1640-C2.jpg"*

*Partial EXIF:*
Date time: Oct 24, 2017 17:16:22
width 5200
height 3902
Photometric Interp: Unknown (32803)
Pixel height 3888
Pixel width 5184
Component YCbCr
Exposure: Normal Program
Scene capture Standard
mode: Auto exposure
bias: 0.00 ev
time 1/320
ISO 200
Metering: Center weighted average
Gain control: Low gain up

This image has a serious fogging issue caused by stray light within the body.  Immediately after seeing this image I started looking for a lens hood.  My next projects were done with a rubber lens hood, but I have a metal lens hood on order.

When adapting lenses that have significantly larger coverage than sensor size, one can expect that body flare can become significant and that an appropriate lens hood will be beneficial.  This 28mm lens was intended to be "wide angle".  In normal Micro 4:3 usage (full sensor) it is roughly a "standard lens" (56mm) and in 4K video for the Yi-M1 it becomes a 78.4mm equivalent short telephoto.  For these latter uses, "narrower" lens hoods become appropriate.  But all the light from the designed "wide angle" coverage is coming into the body.  Depending on how well "baffled" the body is, light can then be reflected onto the sensor.  The "56mm" equivalent use should be perfectly paired with a standard lens hood.  The "78.4mm" equivalent use is harder to match.  An 85mm lens hood might cause vignetting depending on how "tightly" it has been designed.


*Fotodiox PRO MD - MFT" adapter MFR # MD-MFT-P (~$60 US)*
As for the Fotodiox adapter,  overall, the construction is based on two main pieces.  The body of the device appears to be forged, and with minimal machining.  The rear mount (to the Micro 4:3 camera) is part of the main body.  It cannot be removed and can be considered unrepairable.  The front "lens" mount is a separate fully machined piece.  In theory, it could be repaired, but I doubt if the repair part will be made available.  Overall, it is probably intended to be disposable.  This is a problem with this device because the rear mount is not as tight a fit as I would have liked.  I tried to "rock" the lens in the mount and it seems secure enough, but how long it will last will depend on how fast the black coating and the underlying metal might wear out.  Oddly, a standard Micro 4:3 rear lens cap will not work on this mount.  It is too lose and would easily fall off.

The adapter has a tripod mount (which I believe can be removed, though I have not tried to do so), but the front-back length of the mount is short (about 19mm) and I think this could cause dangerous stress in use with long lenses.


----------



## VidThreeNorth

Earlier I mentioned that I wanted to test the touch screen in cold weather.  Due to a cold snap, I got a chance to run a test today at about 10:00 EST.  Temperature was about -7C.  I made a couple of 2-3 min 4K video clips using the "touch screen focus" -- a new feature with the new "Version 3.0-Int" firmware.  There were no problems for this brief test.  I cannot say more than that.  I would take a second camera with me in temperatures below 0C anyway.  Actually I always have second camera, so that is nothing special.


----------



## Braineack

fmw said:


> I think it will find a pretty good market in the U.S.



why?  the sub-par quality images it produces?


----------



## fmw

I didn't suggest that it would find a market with you or me.


----------



## VidThreeNorth

Well this puts me in an awkward spot because I seem to be the only one in this forum who has touched this camera, and I have not really paid it much attention -- not even as a video camera, and certainly not as a "still" camera which I take it is what Braineac is talking about.  If you _are _talking about the 4K video capability, which is why I bought it, well, I would have to disagree.  If used properly, it can produced some nice clips.  Even there I only have a couple of real "work" clips (tagged for a specific project).  Just about everything I have done has been testing.

Let me take a moment and comment about my testing reports.  I do not go out of my way to produce reports for this forum or anyone beyond me.  I go out and test the equipment I have specifically to see if I can use it for specific uses.  I make point form notes as necessary -- again it is all aimed at _me_ and what I need to know.  If I have information that I think will be interesting or valuable "here" (or elsewhere), then I do a little more work to try and turn my notes into something readable (with variable success).  I might make an extra cropped file or resize file or two, but I rarely do more than that.  The images I post are good enough to demonstrate something that I found out along the way.  They may be flawed in other ways, technically or artistically, but they showed something specific that I needed or wanted to know.

Take that "PA240002" file I posted Nov. 3.  That image has so much noise some people might wonder why I used it.  But personally, I can see the lens sharpness through the noise.  I am used to having to evaluate equipment in this kind of situation.  But if it was a situation where, if I were being paid to write a review, I would have waited for another opportunity and taken something better (not that hard really, I just needed a day with better lighting).  But that's the point.  I cannot take more time to make a special set of images for "other people".  It would be nice if I had waited for another opportunity, but unless someone is paying me, I cannot afford the extra time.  So, "good enough for me" is what I posted.

And really, I do have a version of the picture I actually like. I like the wild collage of textures, and there is some subtle eye direction and movement.  But that is after "processing", which mainly was getting rid of the noise....

Braineack said:
> fmw said:

>> I think it will find a pretty good market in the U.S.

> why? the sub-par quality images it produces?

Here I would like some clarification.  Are you writing about the still images in the main reports, or do you mean the stuff I posted "here"?  Because, really, I haven't posted much in the way of still images at all.  Mainly because I have not been using this camera for still images.  Almost everything I have posted has been frame captures.  And there I would have to say that a couple of the frames have shown the camera actually can do well for video.  The 2K video of the "Creepy Crawlies" song turned out quite well, and I have received a couple of compliments from it.  Then again, "taste" being what it is, I have had compliments and a couple of "likes" for the "James Blonde" clip, which is unarguably, "photographically poor".

Also the 20MP "brick wall" file turned out really nicely -- if you like that sort of thing.

As for the formal reports by DP and Image Resources, etc., mostly the JPEGs were done with old firmware, and Yi claims that the "ver. 3.0-Int" firmware does better.  I do not recall having a JPEG file from the earlier firmware to make a comparison, so I will not be able to comment about that.  I am hoping that one of the major reviewers will cover the Yi-M1 again with the latest firmware, so I can find out along with everyone else.  I have just started taking still images with JPG+RAW set, but again, whether I get a good picture out of it in the near future is doubtful.  I have little incentive to make the effort.


*About RAW:*

Now here, the Yi-M1 is about as good as it can be with a good sensor.  If you stick a good lens in front of it, mostly you can get the same image you will get from a top end Panasonic (exactly the same sensor) or Olympus (from what I have seen, if it is not the same sensor, it is certainly not a better sensor).  The only caveats are 1. if you are using auto-focus, the three camera brands work differently, and 2. there is no optical image stabilization (neither lens based nor sensor shift based) in the Yi -- only software (aka "digital") stabilization, and even then, not in either every situation.

I will summarize this:  For still images, from RAW it can, at least sometimes, be as good as the best you can get from a Panasonic or Olympus.  From JPEG?  I don't know, but they are claiming it is "better" now.


fmw said:

> I didn't suggest that it would find a market with you or me.


Well, yeah, now that is a question isn't it?  Exactly who is this camera good for?  Actually, at version "2.0-Int" it was usable, and with practice, and careful use, I have been able to get a foot into the 4K video world.  And at this point, that is all I want.  I still prefer "Full HD".  Also, the 2K (4:3 format) video has been a revelation for me.  I do intend to use that capability.

With version "3.0-Int", I am just now evaluating whether I am going to use it for more than that much.

But would I tell a "beginner" to buy one of these?  I think that having really good autofocus is important for a beginner's camera.  Even with what I have seen so far on "3.0-Int" I do not think it is good enough for a beginner.  But I need to do more testing to be sure.  Right now I would recommend something else.

But if it isn't a "beginners" camera, and it isn't an "experts" camera (which is where I am place you two), then that makes it a good camera for "me" and maybe not much more.  Now, that's a _really_ small market.

Ok, well, maybe it has a good market as a "C-roll" 4K video camera in a general sense.  If they can get some video people to try it out with the new firmware, they might actually have something here.


----------



## VidThreeNorth

Yi Firmware "Version 3.0-Int"

*About the Focus:*

Yi has changed the main focus method.  In versions "1.0.20-Int" - "2.0-Int" focus seemed to consider the whole screen and chose the focus distance that covered the greatest proportion of the whole screen.  This resulted in anomalous focusing, often behind the main subject.  "Single point/touch" focussing was available as an option for still pictures, but not for video.  Now, the primary focus mode is "single point/touch".  When the camera starts, the middle section of the 81 on the screen is selected as the chosen focus area.  Another area can be selected at any time by touching the view screen.  In "touch shoot" mode a still picture can be automatically taken when focus has been achieved (there may be occasional missed focus shots, there were under 2.0-Int, but I have not tested it under 3.0-Int yet).

Face detection and tracking are now available as an alternative in all recording modes.  I have only tested this capability a bit, so I cannot comment on its effectiveness.

Having tested the main focus mode with videos and still pictures, I think the 3.0-Int focus system shows a marked improvement over 2.0-Int and previous firmware.

*About the Exposure System:*

The exposure compensation system however, has both a major improvement and a regression.

Previously, exposure compensation had to be set before a video was recorded and it could not be changed during a video.  Under "3.0-Int" exposure compensation can now be adjusted at any time during video recording.  This is a major improvement.  However, I found that when video recording starts, any exposure compensation setting is "reset" to "+0.0".  So every video clip starts with no compensation.  It cannot be pre-set before a video recording commences.  That means that the start many clips one has to make the exposure compensation and then remove that part of the clip in editing.  This is a very annoying problem, and I hope Yi corrects it quickly.

*Stabilization:*

Stabilization is only available during video recording and only in resolutions from "Full HD" and below.  It does seem to work well within those parameters, but it is more limited than most "optical" stabilization systems, and it also means more "sensor cropping".

*Is the Yi-M1 Good Enough For A Beginner?*

I think that the current focus system could be handled by a beginner with reasonable expectation of success.  The exposure system was adequate back with version "2.0-Int" and, except for the video exposure compensation resetting at the start of every clip, it is even better now that it can be adjusted during video recording.  We can only hope that the video exposure compensation problem will be addressed quickly.

Yes, at around $300 - $380 US (depending on the kit), I think it can be considered for beginners.  But I also have an old Panasonic GF3 sitting on a shelf.  Except for the lack of 4K video, I think the GF3 does better.  The focus system seems more reliable, and has more focus mode options available.  So if I extrapolate the GF3 to the current GX850 would the Panasonic GX850 be worth paying the difference for?  I would say that If I had the extra money, I would still recommend buying the Panasonic, or some of the other possibilities, most of which lack 4K video but would be better still cameras.

*Uploads:*

*"PB210004a-rs1640-C2.jpg"*
This is a 20MP still image taken with the 12-40 Yi zoom is properly focussed, though really it is hard to tell since the depth of field covers almost everything.  Only some very far background objects are easily noted as out of focus.  Exposure has been compensation +1.7 to compensate for the backlight condition.  Other EXIF data: Color representation sRGB, F-stop F5.6, Exposure time 1/250 sec, ISO-200, focal length = 40mm, Max aperture 4.97, metering mode Center weighted average.

*"PB210004b-Crop1640-C1.jpg"*
A full resolution detail crop from the above picture.

*"PB210011.MP4-18h19m09s319a-rs1920-C1.jpg"*
A frame from a 4K video, resized down to "Full HD".  Again, focus is correct even following the motion.  Exposure has been compensated again, though it is not clear by how much.  Probably +1.7 - +2.0.


----------



## VidThreeNorth

Well this is frustrating.  About a week ago I went out and took some still pictures specifically to find out about the Yi-M1's "improved" JPEG support in "version 3.0-Int" and then last night the computer it was on died.  That was the computer I do most of my video work on.  Thankfully, because I still also use a "weaker" computer, I can still get some work done while I wait to fix the broken one, but that might take a week.

Anyway, a few days ago I posted some "close-up" pictures taken with the Yi 42.5mm short-tele/macro lens.  I set that up specifically with a ruler to show the size of the object photographed (about 3" high and about 3" wide).  The next day I decided to do a similar set of pictures without the ruler and slightly different lighting.
"Beginner Equipment Questions"
Beginner Equipment Questions.

For these pictures I forced "F8" and allowed the ISO and exposure time to be selected by the camera.  In the previously posted pictures I "side-lighted" the toy, just to make it different from my usual approach.  This pair is more typical, with it facing the "key-light" (Rembrandt style).

*"PB250001a-rs1640-C1"*
"PB250001.JPG"
Partial EXIF:
Width 5181
Height 3888
Bit depth 24
Color Representation [AdobeRGB}
F-stop f/8
Exposure tme 1/100 sec.
ISO speed ISO-400
Exposure bias 0 step
Focal length 43mm
Max aperture 3.65
Metering mode Center Weighted Average
35mm focal length 85
Exposure program Aperture Priority
Original JPEG file size 6,057,637 bytes


This picture is slightly "front focussed" with the back character a bit out of focus giving it some dimensionality, if you want it.

*"PB250007a-rs1640-C1"*
"PB250007.JPG"
Partial EXIF:
Width 5181
Height 3888
Bit depth 24
Color Representation [AdobeRGB}
F-stop f/8
Exposure tme 1/100 sec.
ISO speed ISO-500
Exposure bias 0 step
Focal length 43mm
Max aperture 3.65
Metering mode Center Weighted Average
35mm focal length 85
Exposure program Aperture Priority
Original JPEG file size 6,624,626 bytes
Created Nov 25, 2017, 13:08:14

This picture puts the both characters within the depth of field.  Dropping further to F11 would have been better, and was within the scope of the lighting.


----------



## VidThreeNorth

Yi-M1 Standard Image:

This is an issue that I have left "hanging" since I loaded the "3.0 Int" firmware.  Does the Yi-M1 generally create good image files internally or do you need to do everything yourself from the RAW file?

The problem is that aside from some technical aspects that are generally agreed upon, this is largely a matter of taste.  Looking at the files posted in the previous post (the Sally and Snoopy images) and the files that I am posting this time, and the other pictures I have taken (still not that many), I think I can say that overall, I think the Yi-M1 does a good basic job of rendering pictures.

This is a picture I took this morning.  It was from my first "snow day" set for this camera this season.  Unfortunately, in retrospect, I misjudged the exposure compensation.  I wanted to maintain the sky (cloud) detail, so I only raised the exposure +0.3 EV.  I think I should have raised it about +1.0 EV.  That means I lost shadow detail, and I had to deal with a lot of noise.  But overall, the Yi-M1's version did well with noise removal, and I did not feel that it "overdid" the processing.

I am posting my own render effort as the main image, but the "detail" crop is from the Yi-M1 created JPEG file.  The Yi-M1 did better then me.

*"PC150013.JPG"*
_- this is the original JPEG file version which has not been posted_

Partial EXIF:
Pixel Height 3888
Pixel Width 5184
Component config YCbCr
Color space Uncalibrated
White Point 0.31  0.33
Primary Chromatics 0.64 0.33 0.21 0.71 0.15 0.06
Exposure program "Normal program"
Scene capture Standard
Exposure mode "Manual exposure" * wrong
Exposure bias 0.30 ev
Exposure time 1/80 sec.
F number f/5.6
Max aperture f/5.6
Focal length in 35mm 80mm
ISO 640
Metering mode Center weighted average
Gain control High gain up


*"PC150013.DNG"*
Conversion parameters:
Temperature 5973
Tint 4
Brightness 1.0



*"PC150013 -1d-Rsz-1641-C1.JPG"*
- This is the version I made from the DNG (raw) file using the following steps:

My Processing:
"Digital Noise Removal"
Noise Correction
- Small 50
- Medium 50
- Large 50
- Correction blend 70
- Sharpen 0

"SmartFix"
Brightness
Overall 4 [Recommended 28]
Shardow 0
Highlights 10
Saturation 19
Focus 60
Black 8
White 12

- I changed the format of the picture removing some foreground leaving a 3:2 image ratio in the final crop before resizing it to 1641 wide.

*"PC150013-JPG-Crop-1640-C1.JPG"*
- This is an unadjusted "detail crop" from the JPEG created by the Yi-M1.

If you check some of the earlier reports by the usual sources I have listed above, the main criticism seem to be "over doing" the noise removal and, I think "over-sharpening".  From the pictures I have seen so far, I think these issues have been well addressed.  The detail crops I have posted recently and in this picture look well balanced.  One might disagree for a particular image -- which happens with all cameras, but overall, it is doing quite well.


----------



## VidThreeNorth

*Yi-M1 "HDR"*
- 42.5mm F1.8 Macro/Portrait lens

This project started when I decided to post some pictures of my Sony a5000 using my Minolta 28-100 zoom.  I expected to take a couple of quick "snap-shots" and post them.  But when I saw the results I was disappointed and ended up working on the DNG files until I got fairly acceptable results.
[see: ""Konica Minolta 28-100mm f/3.5-5.6 D AF Zoom" #9" Konica Minolta 28-100mm f/3.5-5.6 D AF Zoom]

After I was done, it remained on my mind and I had a couple of approaches for improvement.  The first was a simple change in the exposure to EV = +1.0.  The second was to finally try out the HDR capability of the Yi-M1.  Later in the evening I decided that it was a good idea for me to take the extra time and try out the HDR capability of the camera, so the decision was made to continue this as a new project.

One reason I have not gotten around to trying the HDR mode on the Yi-M1 was because the camera does not save a RAW (DNG) file when it is used this way.  I guess that this is probably because it is doing so much and taking its time just making the HDR.  If there were an option to save a RAW, what kind of file would it be?  I would be happy it the camera saved the RAW image indicated by the EXIF data.


*About HDR:*
NOTE:  This forum has a specific area to discuss HDR which I have not had time to look into yet.

As far as I know, "HDR" and "WDR" mean the same thing.  Both terms were coined by people trying to cope with the problem of making pictures where the dynamic range of the subject matter exceeded the inherent reciprocity of the hardware.  The techniques go back to the concepts like "dodging and burning" and other techniques developed in film photography to cope with the same problem.  Some companies might be trying to define certain techniques as one or the other, but I have seen the terms used interchangeably, and I have not seen anyone state a specific difference.  If anyone knows, or even "thinks" otherwise, let me know.


*This Image Set:*

I used a slightly different but similar setup as yesterday, but the lighting is a bit less diffused this time.  For this set of images I also decided to control the depth of field by using "Aperture Priority" and working with F8 and F11, and in the latter pictures selecting the point of focus with the touch screen.

I am not planning on posting "detail" crops for this set.


*"PC210003a-rsz1640-C1.JPG"
*
I started this project with three images taken "regularly" with EV = +1.0 and DNG files.  This is the last image with DNG.  All the rest are HDRs.  This is my "control" image.  If I had taken yesterday's pictures with EV = +1.0 then I would have probably still worked with some of the DNG files, but I would have had an easier time, and probably better results.  I probably would have posted this picture as-is.  There is sufficient shadow detail to show the equipment using the adapter's tripod mount and how high it raises the camera.  I was not trying to make it look "pretty", I was only trying to show the equipment I had been using lately.

Partial EXIF
Dimensions 5184 x 3888
Color representation Uncalibrated (AdobeRGB)
F-stop f/8
Exposure time 1/100 sec.
ISO speed ISO-3200
Exposure bias +1 step
Focal length 43 mm
Max aperture 3.65
Metering mode Center Weighted Average
35mm focal length 86
Exposure program Aperture Priority (forced F8)


*"PC210005a-rsz1640-C1.JPG"*

This file replicated most of the settings of "03" except that it is set for HDR and no RAW.  Notice how that exposure time jumps from 1/100 sec. to 1/5 sec. and the ISO drops from ISO-3200 down to ISO-200.  I did not do that, the HDR setting did that.  Also, the picture is slightly zoomed/cropped compared to the control picture.  If size is critical, one might have to anticipate, and maybe even calculate this difference.  Also, the exposure is still EV = +1.0.  In picture "11" below, using EV = +0, shadow detail starts to go away.  So correct exposure is still a "judgement call" and bracketing is a good idea.  I consider this image to be "almost perfect".  The highlights have been muted bringing out the "AF 28-100" label and the exposure of the bright area on the lens mount is also reduced.  Part of the camera body and parts of the tripod mount are sitting a bit too close to the "floor black" than I would like, but there is no detail of interest in those areas anyway.  Likewise, at the front of the lens there is some silver area which is just inside the "white" value.

Partial EXIF
Dimensions 5184 x 3888
Color representation Uncalibrated (AdobeRGB)
F-stop f/8
Exposure time 1/5 sec.
ISO speed ISO-200
Exposure bias +1 step
Focal length 43 mm
Max aperture 3.65
Metering mode Center Weighted Average
35mm focal length 86
Exposure program Aperture Priority (forced F8)


*"PC210007a-rsz1640-C1.JPG"*

This file has slight composition changes (the angle of view) and F11 is used to increase the depth of field.  The focus distance has been adjusted by using the touch screen focus in order to best use the depth of field.  I tried a few focus points and this one turned out the best.  I do not think there is a good way to check depth of field on this camera.

Partial EXIF
Dimensions 5184 x 3888
Color representation Uncalibrated (AdobeRGB)
F-stop f/11
Exposure time 1/2 sec.
ISO speed ISO-200
Exposure bias +1 step
Focal length 43 mm
Max aperture 3.65
Metering mode Center Weighted Average
35mm focal length 86
Exposure program Aperture Priority (forced F11)


*"PC210011a-rsz1640-C1.JPG"*

This file has another composition changes (angle of view) and it tests setting the Exposure Bias = +0.0.  The average brightness of the image is darker, but the highlights and "floor black" still seem to be "contained."  Comparing the two, I think it is best to adjust the exposure compensation as if it was a normally exposured picture.  The lettering at the front of the lens is falling out of the depth of field, but I think if I had focussed a bit more towards the front of the camera I could have covered it without the "Sony" label losing sharpness.

Partial EXIF
Dimensions 5184 x 3888
Color representation Uncalibrated (AdobeRGB)
F-stop f/11
Exposure time 1/5 sec.
ISO speed ISO-200
Exposure bias +0 step
Focal length 43 mm
Max aperture 3.65
Metering mode Center Weighted Average
35mm focal length 86
Exposure program Aperture Priority (forced F11)


*Conclusion:*

The HDR setting can be useful, but yes, it takes a bit of practice to get the most out of it.  It still helps to set the exposure compensation appropriately.

_*NOTE:*  Due to upload problems the rest of the files were uploaded 2017-12-22 09:31._


----------



## jcdeboever

micro contrast is lacking.


----------



## VidThreeNorth

jcdeboever said:


> micro contrast is lacking.



What are you referring to?


----------



## jcdeboever

VidThreeNorth said:


> jcdeboever said:
> 
> 
> 
> micro contrast is lacking.
> 
> 
> 
> 
> What are you referring to?
Click to expand...

The look of the images. Not impressed at all.


----------



## VidThreeNorth

*Yi-M1 Touch-Screen Focus Test*
_(Partial report -- for now, consider this a partially uncompleted test.  I considered abandoning this test and re-starting it with the "3.0 Int" firmware.  Shortly after I upgraded the firmware, the flowers were gone, so now I would have to pick a completely new subject, or wait till next year.)_

*Firmware version "2.0 Int"
Lens: Yi 42.5mm Portrait/Macro*

In late August I decided that I wanted to test the accuracy and speed of the screen touch focus (and shoot) functions on the Yi-M1.  I thought it should be easy.  I just had to set up the camera on a tripod and use the screen touch to alternate between a "far" focus point and a "near" focus point.  I thought that about 20 pictures of each to get the speed of the focus.  I ran the test twice for about 80 total files.

When I looked at the files on the computer I found out that the "time" on the files were reported down to the minute rather than down to the second.  When I checked the EXIF internal information I found the same thing.  The problem is that I would need many pictures to get a good calculation of the speed.  Or I needed a better method of testing.  I could use a stop-watch (which I have), or perhaps I could set up a camcorder on another tripod behind the test unit and take a video of test.  That would be best because I could post the video and people could see the speed directly.

I never did get around to running the re-test.  But I did have the ~80 files of the test images.

Much later I found that by looking for the EXIF info from the DNG file using Corel Paintshop Pro X7, I could read the file time down to seconds.

The composition was high contrast illuminated flower with white petals against a background of trees, many of which were in shadow.  My first set was done with EV = +0, which was not a terrible choice.  But for my second set I decided that I should expose for the background in order to give the auto-focus a better chance.  I can justify this choice because there are certainly situations when the main subject is in shadow and lightening the images is correct.  Thinking about this later, maybe I should have adjusted the exposure downward for the flower petals, because they were a "real" point of interest and not just an imaginary possibility.

I do not know if the camera can be set to use the "touch" to adjust both the focus and the exposure together.  I think that that would be the best solution.  It might be possible.  I have not gotten that far yet.

Still, that does inadvertently turn this into a "dynamic range test" and I did find out a bit about this camera and its sensor.

*NOTE:*  No "highlight recovery", "noise reduction" or "sharpening" were used in the initial images, so these are "worst case" in those regard.  The "P9030007-2" image was re-converted with an extra correction to the exposure which can be considered an attempt at "highlight recovery".

Unfortunately, the "1640" size detail crops turned out to be too big, and I had to compress them beyond the minimum, so more detail has been lost.  If the file name ends in "C2" it means that I used compression level 2 which is the next step down from "C1" which is minimum compression.  "C4" is two more levels down.  I might try to re-do them again someday, but it might take me a while.

_*[Uploaded 2018-01-13] Correction Files:*
I have uploaded new "Detail" crop files which are 1200 x 900 and saved as JPEG files with "C1" minimum compression.  I will remove the previously uploaded "1640" files later.
_

*"P9030006 -1" [from DNG]*
Temperature 5260
Tint 14

*Partial EXIF:*
ASDK-00129
FlashPix version 01.00
Date and time Sept 3, 2017 17:17:19
Image width 5200
Image height 3902
Pixel height 3888
Pixel width 5184
Component config YCbCr
Color space sRGB
Exposure "Normal program"
Scene capture "Standard"
Exposure bias 0.00 ev
Exposure time 1/640 sec.
F number f/3.9
Max aperture f/1.8
Focal length 43.0
ISO speed 200
Metering mode Center weighted average
Gain control Low gain up

*"P9030006 -1-Detail-Crop02-C1.jpg"*
_[Uploaded 2018-01-13]_
Crop Starting at "0,2100"
- cropped to 1200 x 900 and saved with minimum compression to retain detail.


*"P9030007-1"*
Temperature 5416
Tint 19

*Partial EXIF:*
ASDK-00129
FlashPix version 01.00
Date and time Sept 3, 2017 17:17:21
Image width 5200
Image height 3902
Pixel height 3888
Pixel width 5184
Component config YCbCr
Color space sRGB
Exposure "Normal program"
Scene capture "Standard"
Exposure bias 0.00 ev
Exposure time 1/640 sec.
F number f/3.9
Max aperture f/1.8
Focal length 43.0
ISO speed 200
Metering mode Center weighted average
Gain control Low gain up

*"P9030007 -1-Detail-Crop02-C1.jpg"*
_[Uploaded 2018-01-13]_
Crop Starting at "2000,1400"
- cropped to 1200 x 900 and saved with minimum compression to retain detail.


*"P9030007-2"*
Brightness -1.0
Temperature 5416
Tint 19

*SmartFix*
Overall 15 [Recommended 28]
Shadows -30 [Recommended 0]
Highlights -15 [Recommended 10]
Sat 16 [Recommended 0]
Focus 0 [Recommended 42] *** No sharpening added in order to check the accuracy of the focus.
White Balance OFF
Black 10 [Recommended 10]
White 0 [Recommended 0]


----------



## VidThreeNorth

"DPreview.com" published a review of the Yi-M1 on Nov. 29, 2016.  I have just noticed that they have made the following announcement:

"November 2017: Several issues raised in this review have been addressed in recent firmware. We are now shooting with an updated camera and hope to revise the review to reflect current behavior."

I do not know when this update will be published, but I, for one, congratulate them on their diligence.  As far as I am concerned, the poor state of the camera's original release, and the long time it took Yi Technology to get to the "2.0 Int" and then the "3.0 Int" makes it understandable that few of the "Pro" reviewers have taken on this task.  These reviewers have a lot of other cameras and equipment to test and correctly focus on the products in which their readers have the most interest.  They do not "owe" the manufacturers their attention and efforts.  They "owe" them to their readers.  The originally released firmware, and even up to "1.0.20 Int" were a waste of the reviewers time.

DPreview's Yi-M1 Review page:

New kid on the block: YI M1 review


----------



## VidThreeNorth

On 2017-12-19 Yi Technology released firmware version "3.1 Int".  I missed this one until today.  The update list is short:


"...
NEW
Adds RAW & RAW+JPG shooting format in AE bkt mode

Fixed
Fixed some known bugs, and improved the overall stability of the system. "

I have recently done some video and still work using "3.0" and was about to make some comments.  I will probably post the comments later anyway.  It is likely that there will not be another update for a long time (if at all now), so I guess this will be worth testing.


----------



## VidThreeNorth

*"Read The Manual!"*

I am being partly sarcastic here.  If you did read the original Yi-M1 manual, which was released on Nov. 28, 2016, you did not get much out of it for the effort.  Out of roughly 24 pages, the first half of the manual gets you up to putting in the battery and setting the time and date.  For actual photography they spent only one page for still pictures and another page of instructions for video recording.
_[2018-04-08 replaced "ironic" with "sarcastic" which is more accurate.]_

Yi Technology did provide "online support" by answering common questions and also a forum, but "in the field" unless you had mobile internet, you were stuck with guessing.  Moreover, since that manual was written back in 2016, it did not cover the changes in version 2 firmware.

But with the version 3 firmware came a new "supplement" manual specifically for Video.  Dated Oct. 27, 2017, this short manual (about 9 pages) actually does a pretty good job of describing the use of the current functions.  The current functions combine to change the way one uses the camera.

The change in the approach to using the camera comes from being able to chose between the "still picture display mode" or the "video display mode".  Toggling between these modes is done by holding down the video record button for more than two seconds.


*The firmware favours the still picture mode:*

1. When the camera is turned on, it starts up in the "still picture display mode."

2. If you take a still picture while in "video display mode" the camera drops out of "video display mode" until a video record is started or the display is deliberately changed to the "video display mode" again.

3. When in the "still picture display mode", taking a video will only change to "video display mode" until the end of recording and then switch back to "still picture display mode".

*More Changes*

"Single Auto Focus" is a completely new function.  It focuses when the recording starts but does not change during the recording unless it is overridden.  I believe aperture control is also new.  EV setting was available before but I do not think it could be done during the recording.  The small menu opened by the screen button on the right allows changes to ISO, Focus mode, video format (2K, 4K etc), meter mode, White balance and face detection.  The only control still missing is contrast.


*About Video Auto-Focus:*

From what I understand, the camera always uses a single point for auto focus.  When it is allowed to chose that point, it does look over the whole screen to find it.  When face detection is on, it will favor the point where the face is.  As far as I know so far, it only choses a single face, and it will track that face.  If there is no face, I do not know whether it will "track" whatever was at a focus point that was automatically chosen.  At any time, a manual focus point can be chosen by touching the screen.  This point can also be updated by touching another point on the screen.  To "clear" the manual selection and return to camera chosen automatic focus, the "Q" button it touched.

Manual focus of an electrically controlled lens can be adjusted during a video.

I have found that manually selecting the focus spot is generally the best way to use this camera, though realistically it requires the use of a monopod or tripod.  I almost always use a monopod or tripod, so that has no effect on me.


*Room For Improvement:*

*No "touch focus/with spot meter change"*

The "touch-focus" and "touch-focus-shoot" functions work well but there is no way to change the metering to favour the focus spot.  It would have been nice if there was an option to adjust the meter to the focus spot at the same time.  This would be particularly nice for still pictures.

*A Medium Focus Area Mode:*

It might be a good idea to have an option to reduce the area that the camera considers for finding a "focus spot" from the current "whole screen".  I would suggest a "medium zone" roughly 1/2 the area using the 7 middle rows and the 5 middle columns.

For videos in particular it would reduce the chances of picking a focus point that was "uninteresting".
*
Low Contrast or Log*

It would be nice to have a "low contrast" option for videos.  Since there is no equivalent to "raw" in videos, this has to be done during the actual recording.  Even a simple "low contrast" setting would be an improvement, but a "log" setting would be welcome.  The problem is choosing a "log" response.  There are quite a few, and as far as I know, they are not mutually compatible.

*Firmware Re-Design:*

Lastly, I think that the firmware should further separate video and still picture functions and start replicate the controls.  I would, for example like to have separate date-time stamp settings.  Normally, I would like a date-time stamp on still pictures because I usually take stills for scouting locations and setting up videos.  They are not really for "public consumption".  Other people might prefer the opposite setup.


*Yes, It's Better:*

I think with practice, I am going to like this "3.1-Int"firmware version.  Having the "video display mode" means that I am no longer guessing about the look of a video before I start to record.  Any experienced photographer can understand the value of this.  At this point, I have to wonder if Yi Technology has caught up to their competition in the lower end 4K video capable still cameras.  I can no longer say that a GX850 or Olympus EM10 iii is clearly better.  Olympus and Panasonic still have stabilization to claim superiority, but if you do not need the stabilization, then the Yi controls might actually already be better.  I would have to go back over what has been written about those other cameras to be certain.  And at bottom, the video quality was already quite good when using "2.0-Int".

I do not know how far Yi Technology will push the Yi-M1.  I hope there is still one more upgrade to come.  I would also say now, that I hope Yi Technology is working on a an "M2".  I have no doubt that they have learned enough from the M1 already to make a much better camera, and Amberella already has a better processor chip to work from.

_[22:05]_
I forgot to mention that I now know that for still pictures, "Continuous Auto-Focus" mode stops down the lens for "continuous depth of field preview."  Other mirror-less camera bodies also work this way.  I have to decided whether to switch to working this way in the future.  The problem is that I do not know how much battery power this uses.  The reason I have never used "Continuous Auto-Focus" mode goes all the way back to my first Panasonic Lumix GF3.  The manual warned that it drains the battery faster, and so I always avoided that mode.


----------



## VidThreeNorth

*Two More Requests:*

Since I have asked for specific changes above, I thought that I would add a couple more features which I do not think are currently common, but I have found useful in the past:

1. "Level/Tilt" Indication

Of the bodies that I currently use, the Pentax Q-S1 has level indicators both for "up - down" ("climb - dive" for aircraft) and "left-right side high/low" ("roll" for aircraft).  Personally, I would appreciate it if I could get "roll" markers, but I have no doubt that others like having both types.  This helps setting up a tripod as well as handheld.  I would use a pair of small icons in the upper corners of the display.

2. "Audio Record"

Also, I would appreciate and audio record function so I can record voice memos.  I had a small inexpensive pocket camcorder that had this function.  If this is added to the Yi-M1, then I could make short audio notes mixed in with the still and video files.  It would be particularly useful because they would be in the right order among the videos and pictures to which they would probably refer.


----------



## VidThreeNorth

*Yi-M1 "3.1-Int" JPEG Processing*
Lens used:  Yi 12-40 mm F3.5 - 5.6 kit zoom

The question is "whether the Yi-M1 internal JPEG Processing is any good?"  From what I have seen so far, I think that it is going to end up a matter of taste.  And it will depend on what camera setting are being used, and what alternatives you have for processing raw files.  This is going to take some time and a number of pictures, and I am not going to try to get it all done at once.  In fact, at some point I will probably just stop and consider the question answered.

My camera settings currently are standard "Program" mode, with my choice of EV, and occasionally I will force an ISO in order to get a good exposure time/f-stop combination.  Everything else is automatic or default.  I have not been exploring the available rendering options because up until now, I have only used "raw" capture and processing in various versions of Corel Paintshop Pro (this set of images in 2018).

In "P3030049", the JPEG processing has handled some colour fringing from the lens.  I could have done that, but I did not feel it was so bad.  Likewise, there appears to be some noise reduction and sharpening.  Previous versions of the Yi-M1 firmware have been criticized for going too far with noise reduction and sharpening.  This image, and what I have seen since I started using 3.0 and 3.1 firmware looks typical of my Sony a5000.  If someone makes a formal comparison, you would probably be able to see some differences, but really, it is not that huge.  Look at the tree bark and colours are more muted than the files I made from the DNG.


*"P3030049"*

*"a3030049a-jpg-rsz900-C1.jpg"*

This is a straight resize of the original JPEG created by the camera to give you an idea of what the whole picture looked like.

Partial EXIF
March 3, 2018, 16:08:38
Image width 5200
Image height 3902
Pixel height 3888
Pixel width 5184
Component configuration YCbCr
Scene capture type Standard
Exposure mode Manual exposure _[Actually I think this was "Program" w/EV compensation the same as the other pictures I took that day.  I do not know why it says it is "manual".] *_
Exposure time 1/60
F number f/5.4
Max aperture f/5.4 *
Focal length 33.0 mm
Focal length in 35mm 66 mm
ISO speed 200
Metering mode Center weighted average
Gain control Low gain up
_
* [2018-03-08 21:28 Corrections and additions:
Checking the camera JPEG file in Windows Photo viewer I found "Exposure bias +0.70 ev", which apparently I missed before, and "Max aperture 4.87".  This latter discrepancy might be a bug in Paintshop Pro 2018 version "20.2.0.1 x64".  The "Manual exposure" report error might be from either Paintshop Pro, or the Yi "3.1-Int" firmware.  At this point I cannot tell which.

About the exposure:  As you probably guessed, I deliberately over-exposed this picture because I was interested in seeing shadow detail in the cluster of branches in the upper middle of the picture.  I accepted that there might be clipping since I could see the highlights where the sun was hitting the tree trunks directly.  If I had left the exposure bias "EV = +0.0", I think the highlights would have stayed in bounds.  But these trees are dark and I see them often, so the over exposure produced a result that was interesting for me.  In case you were wondering if there was any indication of the over-exposure, the version 3.0 and 3.1 firmware have a histogram function.  So yes, I could have avoided it.  I just wanted something a bit different this time.]_

*"a3030049-Crop01-C1.jpg"*

This is the detail crop from the original JPEG created by the camera.  All three crop files start from 2270,0 and run 1200 right and 900 down.  This is far on the edge of the picture, which means the lens is outside its best performance, though at 33 mm, it is not far at the end of the zoom range, so it is not at its worst.  I do not find this over processed.  The colour fringing has been handled, noise probably reduced a bit (there was not that much to start with) and particularly, it has not be "over sharpened".  The sharpening is about right.


*"b3030049-1-Crop01-C1.jpg"*

Temperature 5050
Tint 14

This is the converted raw DNG file from Corel Paintshop Pro with no other changes.  Comparing this image to the Yi-M1 and we can see what the Yi-M1 has done.  Oddly, this conversion looks more contrasty.  The light spots on the tree trunk on the right appear to have clipped to white and are surrounded by dark shadows.  Noise in the shadows is not bad.  Overall, it is quite clean.  As I mentioned, since this is far off-axis, there is some color fringing showing up on horizontal branches (this crop is at the top of a vertical formatted picture).  The colour of the tree bark is a bit richer than the JPEG.


*"c3030049-1b-Smartfix-Crop01-C1.jpg"*

SmartFix
Brightness
Overall 33
Shadows -40
Highlights -10
Focus 24
Black 18

Mainly, Smart fix has brought up the shadows and added a moderate amount of sharpening.  Smart fix does not handle the colour fringing nor any noise reduction.  I could have done that separately, but I did not.  Because version 1.x and version 2 firmware did not support saving the DNG raw file and the JPEG file together, this is roughly what I have been seeing out of the Yi-M1 since I bought it.

*"dP3030049-1b-Smartfix-rsz900-C1.jpg"*

This file is a "resize" of the final "Smartfix" version from the raw DNG file.  Is it better than the camera create JPEG?  I think it is.  The colours are a bit richer. But really, there is room for people who would disagree.

But looking at the camera JPEG, it looks similar to a file out of my Sony a5000 subject to the way I have the a5000 set up.  The main difference is that I have set the Sony to automatically handle HDR (reduce contrast).  I think that the Sony would have flattened the exposure of this picture a bit.  I do not see any way to do this in the Yi-M1.  But then again, I do not miss it.


*"P3030002"*

Partial EXIF
March 3, 2018, 15:44:21
Pixel height 3888
Pixel width 5184
Component configuration YCbCr
Exposure program Normal program
Scene capture type Standard
Exposure mode Auto exposure
Exposure bias 0.00 ev
Exposure time 1/250 sec.
F number f/5.6
Max aperture f/3.5
Focal length 12.0 mm
Focal length in 35mm 24 mm
ISO speed 250
Metering mode Center weighted average
Gain control Low gain up

*"P3030002-rsz-1200-C1.jpg"*

I am leaving this topic, at least for now, with this file which has been reduced in size, but is otherwise an un-altered version of the camera JPEG.  The pale beige "grasses" in the foreground are correct.  This is an end-of-winter day and nothing has started growing yet.  There is a faint spot of magenta lens flare in the bottom left corner from the sun.  It is not a processing error.  I have no plan to go through the exercise of comparing it to a processed raw DNG.  It is a nice picture.  Aside from the lens flare, or maybe including that, I doubt if anyone could tell that this was from the Yi-M1 or out of some Sony or Canon.


----------



## VidThreeNorth

*"Portrait Mode"*

When I use my Pentax Q-S1, I use "Portrait" finish because it gives a slight global saturation boost whereas the "Vivid" on that camera" emphasizes some colours.  On that camera, the "Normal" and "Portrait" settings are what I generally use, and I prefer to use "Portrait" if the subject matter allows.

If I were creating a "Portrait" mode, I would set saturation slightly high.  I would set contrast low and sharpening low.  I am not sure what I would do with noise reduction.

_[2018-03-19]
After looking at the resulting pictures, I have found that the Yi-M1 "Portrait" setting is not one I like.  The "blue cast" alone is enough to make it undesirable.  Beyond that, the unnecessary over-sharpening can occasionally cause "halo".  I have no opinion about noise reduction, but it would not surprise me if some people felt it was also too much.  I had planned on further testing of the "Portrait" setting, but I think I will abandon it here._


*Location:*

This is the "Dundas St. West and Burnamthorpe Road" area of west end Toronto.  around this area, along Dundas St. West there are a number of murals.  I am not sure how many, but I think there are at least six.  This is my first scouting trip to photograph them.  Because it was late in the day (~16:30 - 17:00) the sun was low and there were strong shadows.  Over the next few months I hope to return to this area and either get better stills, or record some video stock.  Because of their different orientations of the various murals, it looks like I will have to make a number of trips at different times of the day.

Sadly, many of the pictures turned out poorly because of sun flare.  I am finding this to be an issue when I use this kit zoom.  Yi never released lens hoods for either of their lenses.  As time goes on, I think I will use this kit zoom less and use other brand lenses (with lens hoods) in its place.  I think finding a hood for the 42.5 mm lens should not be a problem, which is fortunate since I have found that lens to be quite good and I hope to continue using it for some time.

*Conditions:*

The temperature forecast for 14:00 - 19:00 was -1 deg C. and breezy.  Rush-hour traffic was a minor annoyance, especially when I photographed across a busy street.

All pictures were taken with a monopod.

All JPEG pictures with names ending in "C1" are minimally compressed and retain the most detail possible.

All processing was done using Corel PaintShop ProX9 on a Gateway DX4375 with AMD A6-5200 APU and Windows 8.1


*"P3160009.JPG"*

*Partial EXIF*
Date and time March 16, 2018 14:51:46 [I forgot to set DST, so actually the time should be 15:49:xx]
Pixel height 3888
Pixel width 5184
Component configuration YCbCr
Colr space Uncalibrated [AdobeRGB -- all my pictures are re-encoded to sRGB by PaintShop Pro during output to the new JPEGs.]
White point 0 31  0 33
Primary Chromataticities 0 64 0 33 0 21 0 71 0 15 0 06
Exposure Normal Program
Scene capture Standard
Exposure mode Auto exposure
Exposure bias 0.00 ev
Exposure time 1/640 sec.
F number 1/10.0
Max aperture f/5.5
Focal length 27.0 mm
ISO speed 200
Metering Center weighted average
Custom rendered "Custom processing" ["Portrait"?]
Gain control Low gain up

*P3160009_jpg-rsz1230-C1*
- resized, no other adjustments

*"P3160009a-Crop01-C1.jpg"*
Crop01 starts 2150,2390
- 1200 x 900
- no other adjustments

I do not know whether the sharpening and noise reduction for the other finishes are the same as the "Normal" finish.  I would have to repeat pictures with the different settings to tell.  This "Portrait" setting picture seems to me to have a bit more sharpening than what I saw in the "Normal" pictures.  The red "State Farm" sign had some over-sharpening haloing where it touches the blue sky, but that was the only instance I could find.  Overall, I would probably sharpen it a bit less.  It is not unpleasantly sharp, but I think, maybe a bit more sharpened than necessary, and lately, I tend to use less adjustments whenever possible.  I included a lot of shadows in the detail crop to show the noise reduction.  The amount of noise reduction here is appropriate for this picture.    It could be argued that noise reduction is higher than necessary.  I have not checked the DNG raw file yet, but I do not think there was any significant detail lost.

_[2018-0323 9:25]_
*"P3160009 -1g-rsz-1230-C2.jpg"*
_This is the corrected version of "P3160047_jpg-rsz1640-C1.jpg" which I uploaded 2018-03-19 in the "2018 Toronto, Winter" topic of the Landscapes gallery.  This corrected version was made from the DNG (raw) file and so it is not related to the "Portrait" version posted here.  The main point of interest is the difference in colours.  PaintShop Pro X9's RAW converter chose the white balance and color set using the "Auto" setting, and the resulting file was further adjusted in SmartFix.  The point of this file is that for the colour and exposure choices, it is the result of "default automatic" adjustments just as can be done within camera firmware.  In theory, there is no reason why the Yi-M1 could not have created the same colours._

_[2018-0319 9:35]
I have posted a further corrected version of "P3160047_jpg-rsz1640-C1.jpg" at "2018 Toronto, Winter".  The further corrected version was manually darkened in order to preserve saturation in the upper half of the mural.  I also have more images of the murals in the area posted there.
_
*
"P3160047.jpg"*

*"P3160047_jpg-rsz1640-C1.jpg"*
- resized, no other adjustments

*Partial EXIF*
Date and time 2018-03-16 15:09 [I forgot to set DST, so actually the time should be 16:09:xx]
Program name: ASDK-00141
Pixel height 3888
Pixel width 5184
Color representation Uncalibrated [AdobeRGB -- all my pictures are re-encoded to sRGB by PaintShop Pro during output to the new JPEGs.]
F-number 1/7.1
Exposure time 1/250 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 15 mm
Max aperture 4.03
Metering mode Center Weighted Average
35mm focal length 30
Exposure program Normal

Since this is St. Patrick's day weekend, I thought I should include a picture of a pub.  This pub happens to have one of the murals.  Unfortunately, when photographed from across the street, the mural is blocked by a bench.


*"P3160055.jpg"*

*"P3160055_jpg-rsz1640-C1.jpg"*
- resized, no other adjustments

*Partial EXIF*
Date and time 2018-03-16 15:13 [I forgot to set DST, so actually the time should be 16:13:xx]
Program name: ASDK-00141
Pixel height 3888
Pixel width 5184
Color representation Uncalibrated [AdobeRGB -- all my pictures are re-encoded to sRGB by PaintShop Pro during output to the new JPEGs.]
F-number 1/6.3
Exposure time 1/250 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 12 mm
Max aperture 3.64
Metering mode Center Weighted Average
35mm focal length 30
Exposure program Normal

This mural is the one in front of the pub.

*
"P3160041-1c-rsz1640-C3.jpg"*
_[Added 2018-03-26]
*NOTE: This picture is NOT an example of Yi-M1 "Portrait" mode.*_

The original colours would have been acceptable, but since I needed to bring up the exposure of the mural I started with the DNG raw file and allowed PaintShop Pro X9 select the palette.  As I noted, lens flair was a battle for this project.  I am in the process of choosing a lens hood for the kit zoom.


*Re: Continuous Auto-Focus:*

This was also my first use of "Continuous Auto Focus".  The experience was not one I enjoyed.  If I zoomed quickly the display flickered.  That was not a serious issue.  The camera locked up once during the middle of the project.  I removed the battery and when I powered up again, everything was fine.

The focus tends to lag.  If I touched the shutter button then the lens would jump into focus.


*More Changes I would recommend:*

These are the last changes I would recommend to Yi:

*1.  "Silent shutter mode"*  This mode would bypass the mechanical shutter.  The traditional reason to do this is to reduce "shutter shock" blurring.  Personally, the reason I want this feature is because it saves power.  The shutter is probably not necessary in many instances.  There has even been some speculation that future mirror-less cameras might not have these mechanical shutters.  I can see an advantage sometimes, but yes, I would like to have the option to bypass the shutter on demand.

*2.  "PNG" file output*.  JPEG arose back when we were using 720MB floppy disks.  We are well past that.  Yes, there are still times when JPEGs are handy.  The best compressed PNG file is still about twice the size of least compressed JPEG.  But I can conceive of times when I would be happy just saving a file in the non-loss-y PNG format.  PNG is the current non-loss-y format for the Internet.  When I used the Yi-M1's HDR capability, after all the effort the camera made putting together a good HDR picture, there was no option to save it except subject to JPEG quality loss.  Why force us to use an image format that necessarily loses quality?

*3.  "Depth of Field Preview for Single AutoFocus mode"*  I did not like the "continuous autofocus" mode.  First, I am still not sure how much power I am wasting, but I am aware of it.  Also, the inability to keep up with a fast zoom change (which caused flickering) was a small annoyance.  The fact that auto focus did not "keep up" while using this mode (it can be "caught up" by touching the shutter button, but that means it is not so much better than just using single autofocus mode in the first place).  Also, there is no way to force the aperture open during this mode for a quick check of where the camera is actually focussed.  Both open and stopped down aperture conditions are useful for photography.  Being forced to only have one of these conditions available is less desirable.

What I would prefer is that during "Single Autofocus" mode, I could select an option that would work like this:

When I press the Shutter Button down "half way":
- First the focus would be set.
- Second, the lens would stop down to preview the depth of field
- Third, the aperture would stay stopped down until I un-depressed the shutter button, or if I further depressed the shutter button, then the picture would be taken.

These and the ideas I posted earlier are all the most important changes I would like to see.  They have all been bouncing around in my head from early when I was using "Version 2.0-Int" firmware.


----------



## VidThreeNorth

*"Vivid"*
Yi-M1, firmware version "3.1-Int"
Panasonic 14 - 42 mm, 3.5 - 5.6 H-FS014042 zoom lens
Monopod

I am a lot happier with the result of the "Vivid" mode than I was using the "Portrait" mode.  The colour balance, saturation and contrast are all well selected.  Sharpening might be a bit higher than necessary, but I did not see evidence of over-sharpening, so leave that with a question mark.  Noise reduction is another area where there is room for disagreement.  It does seem higher than necessary, resulting in some loss of detail.

This set of files was made with a Panasonic 14 - 42 mm, 3.5 - 5.6 H-FS014042 zoom lens.  This is one of the older "kit zooms" and I do not think it is currently available.  It has optical image stabilization, but the Yi-M1 does not support that capability.  Optically it is only a bit better than the Yi-M1 (not as much as you might have expected), yet it actually is a much better lens, not just because of the image stabilization, but because the movements of the elements do not "reverse".

In most of the kit zooms I have tried, when you are zooming from wide-angle to telephoto the front element moves back a bit and then moves foreward.  This is what I would call a "complex" cam-actuated movement.  The problem is that the torque required to turn the zoom control ring changes at the point where the elements reverse direction thus making it hard to maintain a consistent zoom movement for video.  Also, the Yi zoom is probably not a true zoom.  I have not tested for focus shifting during zooming, but I expect that there is probably enough to be visible unless autofocus is able to keep up and correct it.  The Panasonic zoom does not have the "complex" cam-actuated movement, but I expect that it too probably will show focus shift when I get around to testing it.
_[2018-06-20 clarification]_


*About the Yi Lenses:*

I have actually come to like both the Yi lenses.  The zoom has done better overall than I expected despite it being less than wonderfully sharp as noted by the better camera testers.  I think that it boils down to it being just within range of usable software enhancement.  The 42.5 mm lens has been a real bargain.  Yes, I wish it had a focus ring, and yes I would have preferred it to have used some better materials, but the auto-focus and aperture selection have worked well, and really the sharpness is quite good.  I have been pleased with the optical characteristics overall.


*Processing:*
Corel PaintShop Pro X9

Resizing was variable.  I decided that these files were good enough that I wanted to upload the best versions that I could.  So in many cases I tried more than one size, trying to get the largest images that allowed "C1" compression which retains the most detail.

NOTE:  My names are not necessarily the official names of the various murals.  I might change them later.

_The name of the artist who painted all of these murals is "John Kuna".  I tried searching that name in Wikipedia but did not turn up anything.
[2018-06-17]_

*"P3240002a-rsz1600-C1.JPG"*
"Fox & Fiddle Pub"
Partial EXIF:
Date taken 2018-03-24 09:08
Program name ASDK-00141
Dimensions 5184,3888
F-stop f/9
Exposure time 1/500 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 15 mm
Max aperture 3.71
Metering mode Center Weighted Average
35mm focal length 30


This is much better than the previous version.  It can be argued that the lighting was better this time, but even taking account for that, the colour selection is much improved.  Overall, there is no "blue cast" to this set of pictures.

*"P3240002b-Crop01-C1.jpg"*
- detail crop of above


*"P3240020b-rsz1440-C1.jpg"*
_[2018-04-08 "P3240020a-rsz1240-C1.jpg" has been replaced.  The new version is the largest I can upload]_
"Cemetery" [Left 3 panels]
This has the most vibrant colour set.


*"P3240030a-rsz1640-C1.JPG"*
Partial EXIF:
Date taken 2018-03-24 09:16
Program name ASDK-00141
Dimensions 5184,3888
F-stop f/9
Exposure time 1/400 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 14 mm
Max aperture 3.63
Metering mode Center Weighted Average
35mm focal length 28

"Skating"
This is one of my favorite murals.


*"P3240044a-rsz1640-C1.JPG"*
"Radial Line"


*"P3240051a-rsz1200-C1.JPG"*
Partial EXIF:
Date taken 2018-03-24 09:26
Program name ASDK-00141
Dimensions 3888,5184
F-stop f/8
Exposure time 1/400 sec.
ISO speed ISO-200
Exposure bias +0.3 step
Focal length 28 mm
Max aperture 4.55
Metering mode Center Weighted Average
35mm focal length 56

"Sledding"
This is another of my favorite murals in this series.

*"P3240051b-Crop01-C1.jpg"*
- detail crop of above
[I might make a version from the DNG raw file to compare later.]


*"P3240086a-rsz1230-C1.JPG"*
Partial EXIF:
Date taken 2018-03-24 09:48
Program name ASDK-00141
Dimensions 3888,5184
F-stop f/5
Exposure time 1/250 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 15 mm
Max aperture 3.71
Metering mode Center Weighted Average
35mm focal length 30

"Apples"
This panel has one of the richest colour sets, but is more natural than the "Cemetery" panel above.


----------



## VidThreeNorth

*Yi-M1 Dynamic Range*

There are two specific issues I have been planning on addressing since I started looking into the Yi-M1 JPEG capabilities.  One is "dynamic range" and the other is "noise handling v. detail".  These are related, but I am trying to address them individually.  Looking at "dynamic range" here, I am only looking at the "Natural" finish.  If I look at the "Vivid" finish or the others,, the results might turn out to be different.


*"P3030025-1b-rsz1200-C2.jpg"*
The golf course at Eglinton Ave. W. and Jane St.

My eyesight is pretty bad.  Even with my glasses I cannot see a lot of detail.  So if I have a camera in my hand, sometimes I take a picture of simply to look at it later.  When I was photographing the trees north of the golf course at Eglinton Ave. W & Jane St., I was looking up and wondering if there was anything interesting to see in the shadows.  So I took "P3030049" [see also message #34 above].  I chose an EV compensation to get enough exposure into the shadows, expecting that I might lose some highlight areas.
*

"P3030049-Crop02-C1.jpg"*
[Crop from 540,2300]

This crop was all that I was really interested in seeing.  After seeing it, I was satisfied that, really, there was not much of interest after all -- just some branches with pine cones and needles.  That was going to be the end of that picture.  I might even have deleted it at that point, but I decided to keep it for a while.

As I was thinking about writing a bit about the Yi-M1's current JPEG processing, I looked through the files I had on hand and felt that this file showed a handful of issues I thought I would like to show.  In particular, I was interested in the chromatic abberation issues.  First, the 12-40mm kit zoom may not be wonderfully sharp but at the telephoto end in particular there was very little chromatic abberation.  But there was enough to show the way the Yi-M1 handled it.  It also showed a bit of the noise and resharpening issues.  So I decided to use it as one of my first examples.

Having used it for this, I started thinking about the other issues that it demonstrated.  "Gee, it sure is too bad I didn't have the highlights covered by the dynamic range."  Now that raises a couple of interesting questions.  Exactly how much dynamic range does the Yi-M1 have to work with?  Did I have enough that I could have "contained" the whole of this scene?  Whenever I had the time, over the last few days, I chased after the the answers to those questions, and this is what I can say for now:

First:  If I had paid better attention to this picture, could I have set an exposure that would have covered the whole of the dynamic range in this situation?  After trying my best with Corel PaintShop Pro 2018, I can say that no, it was not possible.  It was close though.  First, we know that I clipped the highlights.  It does not look too bad.  As I wrote above, I think an uncompensated exposure probably would have been enough to cover the highlights.  But what about the darkest parts?  I tried compressing the gamma curve using PaintShop Pro's "Histogram Adjust" capability, and then made a further fine adjustment in "Smart Fix".

What I found was that there were a couple of very small patches of un-correctable "black" in the deepest shadows.  Raising the levels of those areas eventually just shows noise.  So that answers it.  Even with the small patches of overexposed highlights at the top end, there is also unusable "black" at the bottom end.  The sensor's dynamic range is exceeded at both ends.  Lowering the exposure to bring down the highlights would simply have increased the black areas in the shadows.


*"P3030049-5c-Crop01-C1.jpg"*
[Crop from 540,2300]

This is the best I could do adjusting the gamma curve to flatten the dynamic range and recover everything possible in the shadow area.  Compare this to "P3030049-Crop02-C1.jpg" and yes, I think that I did manage to recover a bit of shadow detail, but not really much.  I "think" I recovered detail?  Well, if you look at it, the only thing for certain is that the noise is showing up, and there is some "greenish" area that used to be "black" in the original JPEG.  I can "guess" that I am seeing more of the needles, but I am simply applying an assumption that it should be more needles.  An "unbiased" analysis would conclude that "nothing was proven."  But in the end, yes, you will find that there are still some patches that are definitely nothing but "black + noise".


Still, the camera did pretty well.  According to "YI M1 Review" by Mike Tomkins ("Imaging-Resource.com" posted: 09/18/2017)
"YI M1 Review"

The Yi-M1 has "... the same image sensor as in the Panasonic GX8".  I do not have a reference, but I believe I also read that this is the same sensor which is used in the current Panasonic GH5.  It might also be in the G9.  Looking further, DXOmark had this to say about the Panasonic GX8:

DXOmark GX8:
Overall Score 75
Portrait (Colour Depth) 23.5 bits
Landscape (Dynamic Range) 12.6 EVs
Sports (Low-Light ISO) 806 ISO

[Compared against Panasonic Lumix DMC-GH4 (16MP), Olympus OM-D E-M1 (16.3MP), Olympus PEN E-P5 (16.1MP), Olympus OM-D EM10 (16.1MP) their review continued as follows:]

"But the difference between the sensor performance of these Micro-Four-Thirds cameras is so negligible that we can essentially say they offer the same image quality in terms of Color, Dynamic Range and ISO, despite the fact the GX8 benefits from greater resolution."

I think that the sensor performance of the Yi-M1 would prove to be in this same ballpark, which is still about the same as some cameras which cost much more.


----------



## Braineack

VidThreeNorth said:


> I think that the sensor performance of the Yi-M1 would prove to be in this same ballpark, which is still about the same as some cameras which cost much more.


My Google Pixel phone performs better...


----------



## VidThreeNorth

Braineack said:


> VidThreeNorth said:
> 
> 
> 
> I think that the sensor performance of the Yi-M1 would prove to be in this same ballpark, which is still about the same as some cameras which cost much more.
> 
> 
> 
> My Google Pixel phone performs better...
Click to expand...


Well that was an interesting comment, so I took a bit of time to look into it, and came away with a bit of a headache.

The only source I had time to look up was DXOmark, and I ended up bogged down trying to get a handle on their current testing and reporting method.  Put simply, I could not find a specific test of "Dynamic Range".  Yet they had no problem knocking the Google Pixel for apparently not being very good in that category for video.

Here's their link:

"Google Pixel: Retested with the new DxOMark Mobile protocol - DxOMark"

Here are some of the things they wrote in summary which I might be related to "dynamic range".

*Photo:*
"Exposure and Contrast 90
..."
_- [one of the best cellphone cameras for this]_

Pros:
"•Very good highlight preservation
•Very good detail in low light
•Good noise levels in bright and medium light
..."

Cons:
"...
•Very low levels of detail for medium- and long-range zoom
..."

*Video:*
"Exposure & Contrast: 83
..."
_- [83 does not sound so bad.  I need to look at a bunch more to see why they say it lacks dynamic range below.]_

Pros:
"•Good exposure in almost all light conditions
...
•Good noise reduction and color at all light levels"

Cons:
"•Lack of dynamic range
•Visible color shading in indoor conditions
..."


So it sounds like you are might be right about the "Photo" capabilities of your Google Pixel, but for video it got knocked specifically for dynamic range.  In the end, one cannot assume that a smaller sensor in a particular phone camera will be out performed by a particular larger sensor in a camera, and the later technology sensors like in the Google Pixel could be up to the task.


----------



## VidThreeNorth

*Yi-M1 Noise Reduction:*

First, let me say that I have not used typical "image noise reduction" functions much -- in my whole life.  Well that sounds really dramatic, but if you consider that I have only been using image modifying software for maybe three or four years now, you realize that this was mainly a joke.  I am excluding "paint" style programs from this because I have done "paint" work for many years, but photo retouching software is something I only really started using recently.  Oddly, I had software years ago, yes, legally bought and paid for, but I did not even get around to installing it.

_[2018-0410 BIG Mistake, embarrassing but not really important to anyone but me.  I was very tired and in a hurry when I wrote this post so actually, I made 2 big mistakes.  This one is not really important.

What I was thinking about was that I started using "Corel PaintShop Pro" about that long ago.  For some reason I discounted my use of another program that came with a "Nero" installation which was a very nice, but not as advanced image manipulation program, which name escapes me right now.  But I used that for many year -- over five years?  I switched to PaintShop Pro because Nero dropped support of that earlier program.  And yes, as I wrote above I had another program, I think by Magix, which I never even installed.]_

But let me get more specific.  I have probably only used "image noise reduction" functions about a half dozen times over the last three years.  Here is why:

As most of you who have tried out image processing software fairly thoroughly will know, if you use a "rotation" or a "geometric perspective correction" or a "lens linearity correction" (for "pin-cushion" or "fish-eye" or "barrel" distortions), or a resize downward, then a lot of the noise will be "handled" as a result of those changes.  Since almost all my pictures require some combination of these changes, there is usually not much image noise left that requires specific attention.

The result is that I have very little experience with any of the noise reduction tools that I have had in any of the programs I have used.  So likewise I have very little to say about noise reduction for the Yi-M1.  It surprised me at first that I read some comments that the Yi-M1 used too much noise reduction which result in loss of detail, BUT others seem to say the opposite, that the Yi-M1 did not apply enough noise reduction.  At first I attributed this to the possibility that people were seeing different versions of the firmware, and that may be a part of it.  But this comment makes me think that something else might be happening:

DPreview.com "New kid on the block: YI M1 review" 2018-04-08:

"The JPEG engine produces JPEGs that are full of nice detail but some of the finer detail tends to get a bit muddled as it appears that they are applying larger radius sharpening during JPEG processing."

and later:

"In terms of noise reduction the M1's JPEG engine takes a fairly lazy approach, leaving behind a lot of noise and generally not balancing detail retention and noise reduction as well as the Olympus _[PEN E-PL7 specifically]_ with its context-sensitive approach. Color noise can be problematic with the M1, particularly at and beyond ISO 1600, although it starts to become evident by ISO 800 compared to the Olympus. It's also worth mentioning that the M1's JPEG engine also doesn't completely eliminate all of the color aliasing."

It is a bit irritating that their review did not make clear which version of the firmware that the above applies to, but their review seems to be up-to-date up to version 1.0.20 Int. and possibly up to version 2.0.0 Int.  Moreover, they specifically note for "November 2017" that at least 3.0.0 Int is being tested, which I assume will probably mean that 3.1 Int is probably being tested.  I applaud their efforts.

But first, DPreview.com's comments do sound like what I am seeing, so for now, it appears to me that the JPEG has not changed substantial since around 2.0 Int.  If they notice later changes, I will expect them to make a comment about it.  Actually, if they saw something significantly different, I would have expected them to re-do their "studio" test shots by now.  So I think that their currently posted review probably is the most accurate analysis of the YI-M1's JPEG performance.

_[2018-0410 -- My second BIG Mistake, and this one is important:  I think I have made a mistake in my conclusions about the version 3.1-Int JPEG engine, probably because that I managed to get confused about which picture I posted was which.  The file I posted below is my DNG raw file conversion and shows "colour aliasing" in a few places.  It can be seen in the mortar between the bricks as magenta specks, and especially in the large sign letters which have thin black accent lines running through them which in the DNG conversion come out as a rainbow of coloured pixels but in the crop of the original camera JPEG posted previously, the JPEG engine has rendered them as grey, which is the best that can be done.  If this is what the DPreview article is referring to, then it appears that the version 3.1-Int JPEG engine has been improved.]

[Compare the images posted here with:

*"P3240002b-Crop01-C1.jpg"*
 - detail crop of original camera created JPEG.

"Yi Technology -- Yi-M1"]_

*"P3240002 -1c-Crop01-C1.jpg"*
The detail crop.

I have created a fairly straight forward conversion of the DNG raw file and this is a crop that matches what I previously posted.  If you compare the two detail crops, you will see noise specifically in the blacked out windows, and in the Pub's main sign (which includes a lot of the "color aliasing" mentioned in DPreview.com's article).

How much detail was lost during conversion?  Personally, I do not feel that it was much in this sample, so I am fairly satisfied that overall, the Yi-M1 is generally "passable" in that regard.  But there is another point that should be understood here.  The Yi-M1 was made using a version of an Ambarella chipset.  Ambarella probably has not released much information about their DSP circuitry, and decides what capabilities Yi Tech has to work with.  It is entirely possible that Yi cannot do better than this because Ambarella has not provided them with information sufficient to have fine enough controls to further correct the problems.  So even if their is a further firmware upgrade coming, except for perhaps a better colour balance in the Portrait mode, I am not expecting to see better JPEGs than what I am seeing now.

*"P3240002 -1b-rsz1240-C1.jpg"*
A resized version of the whole DNG converted image.  It will not show any noise because it has been reduced so much.


----------



## VidThreeNorth

I am still exploring the YiM1's new capabilities and testing old capabilities that I did not get around to testing before.  In this case I am testing use of adapted lenses, but with a lens I have not tested before.  The lens is a Pentax SMC M series 50mm F2.0.  This was one of the standard lenses available for the Pentax ME and MX 35mm cameras when they were introduced.

Back in the "old days" when I was using real film cameras, I did not have a special lens testing setup.  I did have a target, but I did not have a large wall space to set it up, so I never got around to trying it.  What I did was not much different than what I do today.  Mainly I point the camera a brick wall to get an idea of some of the more formal characteristics, and then some good colour and black and white subjects.  But back then, because film and development cost money, I was very economical in my approach.  These days, I take a lot more pictures because I can afford to delete them.  Actually, not only can I afford to delete pictures, it is imperative that I do so because it costs me to store them.

But back in the old days, I did not have much opportunity to try out a lot of lenses, so I mainly read the most reliable test reports I could find and saw whatever pictures my friends took and compared them to what I knew.

What I am going to say is my "impression" of the situation back then.  There is a good chance that I am wrong about a lot of it.  Frankly, I don't really care that much because when it comes down to it, I still cannot afford to buy a whole lot of equipment, and my first problem is to get what I can afford.

Anyway, my "impression" of Pentax back at that period was like this.  The screw mount Super Multi-Coat Takumar lenses really were excellent lenses.  That was confirmed by every lens test I ever read by Modern Photography and Popular Photography, and a few other magazines I read.  The first K-Mount lenses were as good.  In fact mostly they were the same lenses in new bodies.  And yes, they were new bodies and not just mount changes.  The K-Mount was bigger and I think they tended to make the bodies thicker in diameter.

When the M-series lenses came out, Pentax re-designed many of them to be smaller.  Here I am going to say something that I know many others will disagree with.  I think that many of the smaller Pentax M lenses were not as good as their predecessor models.  Probably some might have improved.  My "impression" was that colours might have been richer, but they might be softer overall or give away a bit of sharpness or vignetting in the far corners.

It was my "impression" that the older SMC Takumar and Pentax K 55mm F1.8 was a better lens that the M series 50mm F2.0, and moreover, both the 50mm F2 and 50 F1.4 M-series lenses were better than the 40mm F2.8 "Pancake".

Over the last year I have bought both the 50mm F2 and the 40mm F2.8 M series lenses, intending to use them on Micro 4:3.  I got the 50mm F2 at about $40 US.  The front element is nicked far off axis.  I do not think it is affecting the lens performance, but the lens does appear to be softer than a typical SMC Takumar 55mm F1.8 would be.  It is not terrible, but it is a bit under-whelming.

Buying the 40mm F2.8 was very annoying.  I think I paid about $75 US for it, mainly because Kai had recently posted a YouTube clip about how wonderful 40mm pancake lenses were (this time using a Canon for an example).  The old M series 40mm F2.8 is not as good a lens as the later "Limited" lens which would be well worth $75 US (or even much more).  But I paid the high price because I think the price for this lens is going to be inflated for quite a while.  It is legitimately a rare lens, because most people bought the 50mm F2.0 lens, but optically it is just not "wonderful".  I class it as "good".  Not better than that because it has severe vignetting when used on a full size sensor (or 35mm film).  I bought it as a manual version backup lens for my M4:3 version 42.5mm F1.8 Yi portrait-macro lens.

When the "first colours" of Spring, began to show, I had the 50mm F2.0 lens on a Pentax K100D, but without my monopod and had a terrible time trying to take very small early flowers.  I eventually went back to the park with the Yi-M1, first with the Yi 42.5mm F1.8 lens, and then again later with the Yi-M1 with this Pentax 50mm F2.0 lens.  The reason for using the 50mm F2.0 lens was because I did not like using manual focus on the Yi 42.5mm lens (which has no focussing control ring), but the Yi-M1 camera does work really well when using adapted, properly designed manual lenses.  Also, the slightly longer focal length was a bit easier to work with in a park where I did not want to step into the flower bed to get closer to plants.
_[2018-05-12 above 4 paragraphs have minor changes.]_

*Why is The Yi-M1 So Good For Real Manual Lenses?*

The Yi-M1 has really good screen magnification, and in the Version 3.0 - 3.1 firmware that magnification goes beyond 4x to 6x, 8x and 10x.  It works like this:

On the back of the camera, the bottom most button is called the "Q" button, and its function varies sometimes.  During still and video recording it controls magnification.  Each time one clicks that button the screen magnification advances to the next setting and after it reaches 10x, then it re-cycles back to 1x.  So the screen magnification cycles like this: (starting from 1x), 2x, 4x, 6x, 8x, 10x, then back to 1x.
_[2018-05-12 minor edit for clarification.]_

The cycling can be over-ridden at any time by touching the shutter release 1/2 way.  The magnification immediately reverts to 1x.

I have found that I generally use 3 quick clicks to get to 6x and do my focussing, and then touch the shutter release back to 1x and compose and take the picture (or abort).  I can do this very quickly.

NOTE:  Some people prefer "focus peaking" and the Yi-M1 supports this capability.  I have tried "focus peaking" on the Yi-M1, the Sony a5000 and the Pentax Q-S1 and on all these cameras I did not find it helpful.  In fact, it confuses me and I end up making mistakes.

Before the Yi-M1 with 3.1 firmware, my favorite camera for manual focus was the Pentax Q-S1.  Now I prefer the Yi-M1.  So the Yi-M1 has my favorite manual focus control, and it also is also arguably, capable of taking the best pictures of any of my cameras, when used this way.  My Sony a5000 still has some advantages for still photography, but I won't go into the fine differences right now.


*This Set of Pictures:*

This set is really just three variations of the same picture and I should start by mentioning that almost all the in-camera JPEG pictures that I have taken with the Yi-M1 have been with AdobeRGB instead of StandardRGB.  I made a set of tests (only a couple of pictures of each) comparing StandardRGB against AdobeRGB early when I started testing Firmware version 3.0.  What I found was that when using AdobeRGB colour saturation turns out a bit higher.  I have not decided that it is necessarily "better" but rather, I am looking at it as a long term experiment.  I know that really, AdobeRGB was intended for print output rather than "on screen", but for now I have decided to leave this Yi-M1 as my only AdobeRGB camera.  This goes along with the fact that I do not really intend to use it as a still camera anyway.  Part of the "test" was to see if it made any difference to videos, and apparently it does not.  It seems to only affect still pictures.
_[2018-05-12 clarification]_

With this set of pictures, two of the files are based on the AdobeRGB output of the in-camera JPEG render.  The third image was made from the DNG (raw) file using Corel PaintShop Pro X9, and despite the fact that the colours have been adjusted and "brightened", the Yi AdobeRGB JPEG version is noticeably more saturated.


*"P5040013b-rsz1640-C1.jpg"*

Partial EXIF (from JPEG)
Date taken 2018-05-04 13:41
Program name ASDK-00141
Dimensions 5184 x 3888
Resolution unit 2
Color representation "Uncalibrated" (AdobeRGB)
F-stop f/0 [probably F16]
Exposure time 1/125 sec.
ISO speed ISO-200
Exposure bias +0.3 step
Focal length 0mm [50mm]
Max aperture 0 [2.0]
Metering mode Center Weighted Average
35mm focal length 0 [100]
[Finish is "Standard"]

- resized version of in-camera JPEG


*"P5040013a-Crop01-C1.jpg"*

Detail crop from in-camera JPEG
- Start 940,2200 (lower left)
1640 x 1230


*"P5040013-2a-SmartFix-C1.jpg"*

From DNG:
Temperature 5090
Tint 23
- crop from 950,2210 (almost a match for crop from in-camera JPEG)

- One Step Noise Removal (this function is not defined in my documentation)

- SmartFix:
Brightness
Overall 28
Shadows -50
Highlights 20
Focus 78
Black 12
White 18

NOTE:  The recommended "focus" (sharpening) for the DNG without noise removal was "75".  Noise removal only increased it to "78".  Most images taken on the Yi-M1 using the Yi lenses have used sharpening in the range from "35" to "50".  I take this as an indication that this Pentax lens is not as sharp.  The only other pictures I have taken with it so far -- on the Pentax K100D, do seem to indicate this as well.

_[2018-05-12]_
Recently I posted three pictures of flowers taken with the Yi-M1 using the Pentax SMC M-Series 50mm F2.0 lens at:

"Spring, Finally . . . ."

I did not have a chance to pay attention to these pictures earlier.  Looking at them, the lens looks a bit better -- closer to the older 55mm F1.8 .  If you look at "P5040057-1c-rsz1240-C1.jpg" in particular, the sharpness and detail level look much better.  When I checked my processing
notes I found that the recommended sharpening was only "focus 31" which is roughly in the usual range of my Yi 42.5mm F1.8 lens.  So it seems to be about as sharp as that lens.  I have a couple of other pictures that show good to excellent performance at around F8, which is also typical of the 50mm F1.4.  The following are from my processing notes for that picture:

*"P5040057"*
- unidentified blue flowers

Partial EXIF from JPEG:
Date taken 2018-05-04 14:03
Program name ASKD-00141
Dimensions 5184 x 3888
Resolution unit 2
Color representation Uncalibrated [the JPEG was AdobeRGB, but
the version I uploaded was from the DNG raw file processed i
Corel PaintShop Pro X9]
F-stop f/0 [I was trying to use between F4.0 and F16.0
and I think this was probably F16.0]
Exposure time 1/250 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 0 mm [actually 50mm]
Max aperture 0 [actually F2.0]
Metering mode Center Weighted Average
35mm focal length 0 [actually 100mm]

- Conversion from DNG
Temperature 4282
Tint 21

- SmartFix:
Brightness
Overall 28
Highlights 10
Focus 31
White balance Yes
Black 4

- Vibrancy 20


*Which Picture is More "Realistic"?*

Actually neither version looks quite the same as I remember the original scene, but I think the AdobeRGB version based images are closer to reality.


----------



## VidThreeNorth

*Revisiting files taken this Spring.*

YiM1
42.5mm F1.8 Lens
Monopod

_I planned this post weeks ago, but then I covered the issues in another post elsewhere.  I think that was a mistake because where it is possible,  all this YiM1 information should be keep in a single topic where people can find it later.  The number of other people who might buy this camera later is going to be small, but I should still finish what I started properly.  The final incentive to get this done is to remove a lot of files from my computer.  All these Spring files will be difficult for me to access later._

I think I have better cameras than the YiM1 to take this particular picture.  The problem I had was the auto-focus.  My first pictures focussed on the background (ignoring the roses which were nearer).  So I decided to use the "touch focus".  But the touch focus does not track movement and the branches, including the flowers were in constant motion.  I set the lens to Macro which in this case limited the aperture to F3.5 and allows closer focussing, but as far as I know, makes no other adjustments.  So the aperture at F7.1 was not affected by the setting.  I increased the exposure 1/3 stop because a lot of the flowers were in shadows.  After that, all I could do after selecting the focus point was watch the branches waving around in the air and try to take a picture when my actual target was moving into the focus box.  The bumble bee came into the area after I was set up, but I decided not to make any changes (or try to chase the bee around).  This picture caught the bee, but not in a bloom that was well lighted, so there has been a further adjustment of around another 1/2 stop.  I did make a couple of versions using noise reductions, but in the end, neither of these uploads uses any noise reduction.
_[2018-12-13 The Yi 42.5mm lens close focus limits are 19.7" in normal mode and 9.8" in Macro mode.]_

Yes, it would have been nice if I had gotten closer.  Maybe next time. . . .

*"P5020041.DNG"*
- Bumble bee on rose

Partial EXIF from DNG: (PaintShop Pro X9)
Software ASDK-00141
FlashPix version 01.00
Date and Time May 2, 2018, 17:21:19
Image width 5200
Image height 3902
Components per pixel 1
X resolution 72.0 dpi
Pixel height 3888
Pixel width 5184
Component configuration YCbCr
Color space Uncalibrated (AdobeRGB -- irrelevant)
Exposure Program Normal program
Scene capture type Standard
Exposure mode Manual exposure
Exposure bias 0.30 ev
Exposure time 1/250 sec.
F number f/7.1
Max aperture f/3.5
Focal length 43.0
Focal length in 35mm 86 mm
ISO speed 200
Metering mode Center weighted average
Custom rendered Normal processing
Gain control Low gain up

*"P5020041-1-rsz1440-C1.jpg"*
[The whole frame re-sized.]

Corel PaintShop Pro X9 on Gateway dx4375,
AMD A6-5200 APU, Windows 8.1

Temperature 4610
Tint 11
Brightness +1.0

*"P5020041-2b-SmartFix-C1.jpg"*
[Detail crop.]

Crop X=1280, Y = 960
Start @ 1872,1410

Smartfix
Brightness
Overall 24
Shadows -50
Highlights 20
Focus 68
White balance [yes]
Black 12
White 16


Detail crop
No Noise reduction.


----------



## VidThreeNorth

*HDR for Architectural*

YiM1 w/12 - 40 mm F3.5 - 5.6 zoom, tripod
and wide rubber lens hood

When I tried the YiM1 "HDR" capability earlier this year, the first thing I thought of was Toronto City Hall.  I have not taken many still pictures of City Hall.  It is a very dramatic building, and world famous, and it is easy to get a "nice" picture of it, but hard to get a really good picture of it.  Part of the reason is that the shapes cause complex, unavoidable shadows on its internal faces.  As far as dynamic range is concerned, it is a nightmare.  The result of my first test of the YiM1 HDR capability gave me a very nice result I wanted to see what it could do for this situation.

Unfortunately, I have a problem when it comes to Micro 4:3 wide angle lenses.  I do not have one that is "really good".  I have two zooms that reach 12mm (eq 24mm).  The YiM1 12-40 zoom was known to be poor at the wide angle end.  Likewise the Panasonic 12-32 zoom is also not so good at full wide angle.  Which is worse?  I do not know.  I do not have comparable lens test results.  All the tests for the Panasonic lens are old and at best, done on 16MP sensors.  In fact, I think some were tests on 12MP sensors.  My experience with the Pansonic 12-32 seems to indicate that it might be a bit sharper in the middle, but I think it falls off worse in the corners.

This has not concerned me up till now because for video, I have the Git2 which does a fairly usable 21mm eq. view in "near-UHD" at 24 fps, and my Sony Z3c phone which seems to be around 24mm eq, at 30 fps.  Unfortunately, it looks like the "SLR Magic 8mm F4" is not going to be useful, but I have not totally given up on it yet.  For still pictures, I am only "well covered" out to around 14mm (28mm eq), where both the above mentioned zooms are much better.

*Setting Up:*

If you look at the reduced version of the first picture you will see that in theory, I could have zoomed out to 14mm (28mm eq), but if I decide to correct perspective I will already lose a lot of the left and right sides, and the bottom level of the building will be need to be cropped.  I think that bottom level is a part of the whole and should be kept.  So really, I would have preferred to start from a 20mm lens' view.  The camera is on a tripod which extended to about 5' 6".  The wind was a strong gusting breeze which causes some vibration on the tripod, so some motion blurring might also be a factor.  The Vivitar Wide Angle rubber lens hood is minimal, but probably helps a bit.  At this distance, atmosphere can also start to interfere with sharpness, though I do not think that happened in this picture.  Does the HDR processing result in loss of image sharpness and detail?  From my earlier test using the Yi 42.5mm prime lens, I think there might be a very slight reduction in quality, but I do not think it had much effect on this picture.

*Technical Results:*

The results in terms of exposure and colours was very good.  But the sharpness and detail were not very good.  I think the lack of sharpness was subsstantially the result of the lens, with other factors having neglibible affect.  The question I am left with is how interested I am in pursuing this type of HDR photography in the near future?  If so, I need to buy another lens.

Getting back to the exposure, I like the result overall.  I will probably make some small adjustments, but I got a level of shadow detail that I think is nice, without clipping the top end highlights.  I used 1 EV "jumps" in my bracketting.  I think that there is a benefit in "filling in" the exposures by using every one of the 1/3 EV increments.  I might even have gotten a "perfect" result without  any further adjustments.  There is also a benefit in taking more pictures because the tourists were wandering around without regard to my preference, creating different "found" compositions.  The more pictures taken, the more chances one has of getting a "better" picture.

*Miscellaneous:*

Slowly but unavoidably, developers are filling in the backdrop of this view with typical urban clutter.  It looks like the view down the middle is in the process of going away.

*The Flower:*

This is the same camera equipment with the lens zoomed out to 37 mm.  As I have written before, the lens actually performs quite well, except at its wide angle limit.


*"P6140042.jpg"*
[original JPEG not uploaded.]
City Hall HDR

Partial EXIF [original JPEG]
Date and time June 14, 2018 10:28:13
Program name ASDK-00141
Dimensions 5184 x 3888
Bit depth 24
Resolution unit 2
Color representation Uncalibrated [AdobeRGB]
F-stop f/7.1
Exposure time 1/320 sec.
ISO speed ISO-200
Exposure bias +1 step
Focal length 12mm
Max aperture 3.64
Metering mode Spot
35mm focal length 24
Exposure program Normal (HDR)

*P6140042a-rsz1936-C1.jpg*
- resized, but no other changes.

*P6140042b-Crop01-C1.jpg*
- detail crop, no other changes.

*"P6140068.JPG"*
[original JPEG not uploaded.]
- flower

Partial EXIF (original JPEG):
Date taken 2018-0614 10:43
Program name ASDK-00141
Dimensions 5184 x 3888
Bit depth 24
Resolution unit 2
Color representation Uncalibrated [AdobeRGB]
F-stop f/8
Exposure time 1/400 sec.
ISO speed ISO-200
Exposure bias 0 step
Focal length 37 mm
Max aperture 4.93
Metering mode Spot
35mm focal length 74

*"P6140068-1a-rsz1980-C1.jpg"*
- processing: Corel PhotoShop Pro X9

SmartFix
Overall 28
Focus 37
White Balance [yes]
Black 12

---
_[2018-06-19 20:04]_

This picture is being uploaded later because I needed to alter faces.  In fact, I almost decided to skip this picture because it does not really add much real information beyond the earlier pictures.  It was taken about 3/4 of the distance of the earlier picture (to the center "dome") and from a lower angle.  About the only thing to see is that by adding more elements so the picture is "busier", and completing the post processing (adjustments for gamma and sharpening) one gets an illusion of better image quality.  If you look closely though, the level of "fine" detail has not really changed.

Another lesson is that this HDR capability does actually keep up with motion to an extent.  There are people who were walking around and the plants were being moved the breeze, but they do not seem to show motion blurring more than the concrete planter and arches over the reflecting pool.  It makes me curious about how this actually works.  Put simply, this picture could not have been done with traditional sequential bracketing shots.

Lastly, I guess I will say that I consider these "nice" pictures.  So, at least for now, I am still stuck in the "nice" zone, at least unless or until I get a better lens. . . .

*"P6140044.JPG"*

Partial EXIF:
ASDK-00141
Date and time Jun 14, 2018, 10:32:21
Pixel height 3888
Pixel width 5184
Color space Uncalibrated [AdobeRGB}
Primary chromaticities 0.64 0.33 0.21 0.71 0.15 0.06
Exposure Normal program
Scene capture type Standard
Exposure mode Manual exposure
Exposure bias 1.00 ev
Exposure time 1/400 sec.
F number f/7.1
Max aperture f/3.5
Focal length 12.0 mm
Focal length in 35mm 24 mm
ISO speed 200
Metering mode Spot
Gain control Low gain up

*"P6140044c-rsz1840-C1.jpg"*

- Manually obscured faces

Smartfix:
Brightness
Overall 0 [Recommended 4]
Shadows -10
Saturation 7
Focus 41
White balance [yes]
Black 10
White 4


----------



## VidThreeNorth

*John Kuna v. YiM1*

This is a continuation of my test of the various colour choices in the YiM1 and also an update on my pictures of the "Village of Islington" murals.  As I noted, the "Vivid" finish worked much better than the "Portrait" finish.  I posted the "Vivid" set in:

"Yi Technology -- Yi-M1" (see #36)

As I wrote before, I am quite pleased with that set of pictures.  They are "scouting" pictures where I am mainly interested in making a record of "what is there".  In particular, I felt that due to the building orientations I would need to plan the time of day when lighting and shadows were optimal.

Lately I was checking the internet researching the artist (John Kuna).  There was nothing in Wikipedia(yet) but I did eventually find articles about him, and also his own website.

On his website, there are pictures of a number of his works.  What I found most interesting is that there is a strong similarity in the color rendering to what I got from the YiM1 in AdobeRGB and "Vivid" finish.  Have a look and compare them.  Certainly the pictures on his site are better, but the colour sets are very similar.  You can see them at (his website):

"John Kuna Murals"


----------



## VidThreeNorth

You'd think that by now I would have tried all the "relevant" feature combinations on this camera, but there are still a few to go.

I have found that the "Finishes" (Standard, Portrait, Vivid, Natural B&W, H Contrast B&W) can be used for video recording.  I tested them all early in the Summer in Full HD with stabilization and they worked for short clips.  I had intended to try longer clips in 2K later.

This Fall, I decided on a video project using the Yi "2K" (4:3) format with the "Vivid" finish.  I had a number of video clips in the camera and decided to save them off and start the editing.  I have just reviewed most of the clips, and unfortunately, not much turned out.  It appears that the combination of "2K" and "Vivid" only works for a limited extent.  Depending on the clip, most of them "failed" after around 40 sec. recording time.  This varied with the subject matter.  I think it probably has to do with the complexity of the images which varies for each frame.  It is probably over-running a buffer used by the Codec.

Unfortunately, that means that the project (which I was looking forward to) is a bust.

I do think that it is probably possible to use the "Finishes" in Full HD.  I will have to try a longer test clip to be sure.


----------



## VidThreeNorth

I checked back in case there was a firmware update by now and there was one.  The latest firmware is version 3.2-Int.  I have applied the upgrade.  Unfortunately it probably will not help the video problem.  The only issue addressed had to do with Apple's Mac:

_"YI-M1 Release Note
Yi Technology 
Version:3.2-int 
Release date:09/05/2018 
Must upgrade the app to the latest version
(Android:3.1.3+,IOS:3.1.0+)

Fixed 
Fixed an issue where iOS 11 could not be previewed properly."_

Still, I am impressed that an update was released as late as Sept. 5, 2018 for this product which has, apparently been discontinued quite a long time ago.


----------



## Braineack

Why are you still posting about this low-end, low-quality camera no one else will ever buy/use?


----------



## VidThreeNorth

Camera: Yi-M1
Lens: Yi Tech 12-40mm, 1:3.5-5.6
Zoom set ~17mm

According to the previous day Forecast in the Toronto Star, this was going to be a rainy day with no expectation of sun.  I woke up at my usual time (about a hour later than I would if I had planned to record a time-lapse) and looked out at the sky.  It was hard to tell.  I did not see stars at all, but the slightly mottled appearance indicated that there was some thinning in the cloud cover.  Maybe there would be enough gaps to make a good sunrise?

Because I had not anticipated this, I had not kept the battery fully charged.  I was unsure how far down it was.  I plugged it in while getting dressed and went straight to work.


*Yi-M1: A Pretty Good Time-Lapse Camera*

I think the Yi-M1 ties the Git2 as my current "best" equipment for Time-Lapse.  In some ways it is much better, but it also has significant issues that make it less desirable to use.
*
Time-Lapse Specific Settings:*

The Yi-M1 has a specific Sub-Menu called "Time Lapse".  These are the contained parameters:

Time Lapse On-Off
File Retention Settings
 - "Photo Only"
 - "Video Only"

_If Photo:_
Number of shots 0099 (but probably limited by size of card.
I have only seen max "599" w/32 GB card)
Interval Time
- from 1 sec up to 23 hr. 59 min, 59 aec
Delay Shooting Time [delays start of recording]
(up to 23 hr. 59 min, 59 sec)
File Format <"JPG-S" ... "RAW+JPG-L" [All options of regular
still pictures including RAW only]

_If Video:_
Interval Time
- 0.5, 1, 2, 3, 5, 6, 10, 12, 30, 60 [sec]
Continuous Shooting Time
30 min, 1h, 2h, 4h, 8h, 12h, 18, 24h
Video SEttings
3840 x 2160 30P (etc.  All video formats, all at 30 fps)

_[2019-01-17 09:40
NOTE:  When the Yi-M1 saves still images to make into a time-lapse video later, it uses the mechanical shutter, but if the video is being made in the camera, it does not use the mechanical shutter.]_

*Settings Used:*

The following are all the settings I used for today's sample, including those specifically for time-lapse:

*Yi-M1 Settings:*

ISO Auto
White Balance Cloudy
Metering Mode Pattern
Focus Manual
Touch Shooting Off
Face Detection Off
HDR [na]
Drive Mode single
Connection [na]
Time Lapse, [On, Video, 1 frame/sec, 24 hr, 3840 x 2160 x 30 fps]
Video Settings 4K [I assume this is actually over-ridden by the
Time-Lapse specific setting]
Basic Settings [na]
BKT Off
File Format [na]
Image Aspect [na]
Resolution [na]
Flash Mode Off
Card Setup [na]
AF Illuminator [off]
Auto Playback [na]
Display Grid [1/3rds]
Video Stabilization [On]
Firmware 3.2-int

Style "Portrait" [slightly less contrast and saturation?]
Exposure EV= +1.0 [I generally prefer +0.3 or +0.7 and on this day, I think +0.7 would have been best]


*Power Problem:*

The camera does NOT run off AC.  If one plugs in the camera while it is OFF, then the battery begins to charge as needed.  But if the camera is turned on while charging, then the battery stops charging.  The power indicator seems to show that the camera is being powered by the AC, but it is not.  It is actually running off the battery, and the USB power is doing nothing.  This is the biggest drawback of this camera because it limits the camera to 1 battery charge of recording, which for me, at "1 frame = 1 sec", into a UHD and 30 fps file means at best a single 5 min file (roughly 2.5 hours of recorded frames).  I cannot leave it running overnight like the Git2.  It also means that when I am setting up, I am somewhat under pressure, and for a sunrise, still half sleeping, so I can make mistakes and botch the result.


*Quality:*

- When recording UHD at 2 sec. per frame, I have gotten higher ~126,000 kbps data rates.
- When recording UHD at 1 sec. per frame, I sometime got ~80,000 kbps, but sometimes also got 126,000 kbps.
- I am not sure why I got the higher data rate at 1 sec. per frame.  It might have to do with starting when the sky was darker.

*Other Settings and Explanations:*

I used "Portrait" because it seems to use a slightly lower contrast, though it also reduces saturation.
I used "Cloudy" to give it a bit warmer render.
I used "Pattern" metering because the sun could have driven the reading too far dark in "Center-weighted" if it got into the reading area, though in fact, it does not seem to make as much difference as I expected.
I should also mention that the zoom is at ~17mm and I am focused very far away, but not at infinity.


*Results:*

*"P1080001.MP4"*
Created Jan 8, 2019, 13:49:14
3840 x 2160
Length 04:46 (battery charge depleted to red)
size 2,419,250,288 bytes
VLC:
Codec: H264 - MPEG-4 AVC (part 10) (avc1)
Resolution 3840x2178
Frame rate: 29.970029
Decode format 4:2:0 YUV full scale

1 frame = 1 sec.
Portrait finish (confirmed, seems to be lower contrast)
Start ~07:50
End ~09:20

-still very contrasty
- Video Data Rate: 67,669 kbps
Total Bitrate: 67,669 kbps

[This bit rate is below typical for this camera and I think it is specifically the result of the very high contrast with a large near-black foreground.  There is some detail that could be recovered, but I would prefer to let it go black and decrease the brightness of the sky, which would increase colour saturation.]

Actual Sunrise at 01:40 in the clip.


*Other Problems:*

I would prefer to have settings for Contrast, Saturation and Sharpness instead of the typical "Normal, Portrait, Vivid, ..." choices that the Yi provides.  As noted, I chose "Portrait" because it seems to reduce contrast and saturation slightly, but only "slightly" and there is no control for sharpness at all.  The Git2 provides Contrast: High, Medium and Low, and Sharpness, but also lacks specific Saturation control, providing similar "Noraml, Portrait, Vivid, etc." options.  I have other cameras with other controls, but adding Contrast, Saturation and Sharpness would be a major improvement, and if I could add just one on top of what is already provided, it would be Contrast.

*A Possible Alternative:*

Apparently the Nikon Z6 has available a specific "flat" profile output which is not a "log" output.  If it is just a "very low contrast" profile, then I would be in favour of using an identical profile, which would be a convenient standardization.

*
Sample Frame Capture:*

*"01-2019-01-08-10h07m29s304-C2.jpg"*
Dimensions 3840 x 2178
Bit depth 24
Resolution unit 2

This is an unadjusted frame from camera output video clip.  I tried the lowest JPEG compression C1 but the resulting 2.532 MB file was too big to upload.  I decided to reduce it to JPEG compression C2 which resulted in a 1.859 MB uploadable file.  While this results in a slight degradation of the image, I think it is still a good representation of the camera's ability.


----------



## VidThreeNorth

I have avoided posting "UHD" videos to YouTube this long because my limited (25 GB per month) Internet account does not allow me to waste such activity.  I have noted a few times that I do not actually view videos in "UHD".  Most of what I watch is less than 720p, and I watch 720p much more often than 1080p.

This is the second "UHD" video I have posted that was made using the Yi-M1.  I used three lenses, none of which was from Yi Technology.  This is not because I am dissatisfied with the Yi Tech lenses -- actually I like them both, but I needed to use the Panasonic 14-42mm F3.5-5.6 zoom because it is "new".  This "kit zoom" has "plastic-on-plastic" parts, just like the Yi Technology zoom lens, and many others.  Such parts tend to be "sticky" and need to be "worn in".  So I used that lens just so I could "wear it in".

I used the SLR Magic 8mm F4 lens because it was the widest I have, and though I have been critical of its quality, I recognize that it can be adequate as long as editing is simple (changing exposure is ok, but cropping is out of the question).

Finally, I used my 50mm F2.0 SMC Pentax lens because I was planning to use a focus pull.  In fact, I recorded the focus pull, but the tripod was not steady enough, so in the end I cut the focus pull and just used the clip after the focus pull was done.

"[UHD] 20190515 Toronto High Park Cherry Blossoms"


----------



## VidThreeNorth

*About the "2019 Toronto, High Park, Cherry Blossoms" Video:*

The camera work was rushed for a few reasons.  First, I only allocated three days to record, edit and upload this project.  Also, for the recordings, I knew that I had to work quickly to avoid the crowds of visitors to the park.  And then there was the weather.  The cloud cover on the first day turned out perfectly while I was recording, but it cleared by the time I ran down the battery on the Yi-M1, leaving harsh contrast and deep black shadows.  Two days later when I returned, it was similar.


*Part 1* (file 042)

Frame Cap to PNG:
"01-2019-05-26-09h34m04s508.png" [not uploaded]
Size: 12,770,082 Bytes

Convert to JPEG:
"01-2019-05-26-09h34m04s508a-C1.jpg" [not uploaded]
Size: 7,104,546 Bytes

Resize:
*"Part01-2019-05-26-09h34m04s508b-rsz1640-C1.jpg"*

Detail Crop:
Crop Start:
3000,800
Size 1640 x 1230

*"Part01-2019-05-26-09h34m04s508c-Crop01-C1.jpg"*

This "establish" clip is unusual both in composition and in the fact that I actually do not know very much about it.  First, I do not know the focal length, nor the aperture, nor the exposure time.  I picked the location moving the tripod and camera around trying to get the crest of the hill in the picture, and the foreground trees, all forming a window-like appearance.  Then the focal length was adjust to crop the scene, and I did not record it.  The aperture and shutter speed were automatic.  I can guess that the ISO was 200, because that is where it stays for typical daylight exposure.

I also do not know where it is focussed.  In a situation like this, I have found that the Yi-M1 usually focuses on the background, but on occasion, it picks something near and throws the background out of focus.  When I setup the composition and looked at the focus, it looked sharp all through on the screen, and I accepted it without manually picking a focus spot.  I thought that I would be able to find the focus later, but I have not been able to do so.

I think that it might have picked the crest of the hill in the foreground.  The bark on the tree to the far right in the detail crop looks particularly good.  Looking at the branches in that tree, some of them also look very good.  The aperture must have been on the small end because even the cherry blossom clusters in the background seem to have some distinct shaping, yet there is noticeable softening past the foreground trees.  Part of the "softness" is caused by the Y'CbCr 4:2:0 chroma sub-sampling and is used in typical video, and that disguises the focus too.

Was there something about this Panasonic lens that added to the preference to focus in the foreground?  I do not think so, but I cannot say for certain.

---
*Part 2*
Capture to PNG:
"01-2019-05-26-10h24m45s856.png" [not uploaded]
Size: 11,150,185 Bytes

Convert to JPEG:
"01-2019-05-26-10h24m45s856a-C1.jpg" [not uploaded]
Size: 6,256,175 Bytes

Resize:
*"Part02-2019-05-26-10h24m45s856b-rsz1640-C1.jpg"*

Crop:
*"Part02-2019-05-26-10h24m45s856cCrop01-C1.jpg"*

The recording situation for this clip was similar to the first, though I adjusted the tripod location based on the start and end of the pan.  Unfortunately, I did not have a good tripod for this project, so it did not turn out as smooth as I would have liked.  I wanted to have as many cherry trees as i could get in the composition at the end of the pan.

Again, I do not know the focal length, aperture, shutter speed, nor the ISO.  I made the adjustments and then did not take the time to note them.  I think that when this frame was taken, the camera was probably focussed on the main cherry tree that fills a large part of the right side of the image.  If you check the detail crop, the garbage bins in the bottom right are suspiciously sharp, but the grass around the base of the tree is detailed enough to indicate that the tree might have been the real target.  But even the signs past the tree show that the depth of field was allowing a lot of leeway.

The clouds were clearing quickly and I was lucky to get a set that I felt was perfect.  It is ironic that this 2 min. short is particularly calming and relaxing, but the actual recording was tightly scheduled and rushed.

---
*Part 3*

"01-2019-05-30-10h11m52s075.png" [not uploaded]
Size: 11,889,336 Bytes

Convert to JPEG:
"01-2019-05-30-10h11m52s075a-C1.jpg" [not uploaded]
Size: 6,191,561 Bytes

Resize 1904 x 1080:
*"Part03-2019-05-30-10h11m52s075b1-rsz1904-C1.jpg"*

Crop01 from top right
1640 x 1230
*"Part03-2019-05-30-10h11m52s075c1-Crop01-C1.jpg"*

This part was recorded on May 17, which was the due date.  The original clip I recorded was borderline.  It was taken with the Panasonic lens and the autofocus could be seen "seeking" a bit.  The focus was overall a good compromise "hyper focus", but the closest branches sometimes looked a bit soft.  The clip was good enough, but I wanted to see if I could do better.  So I went back with my Pentax 50mm F2.0.  I tried a "focus pull" but again, my tripod was inadequate and merely touching the lens caused visible shaking, so I used the extra time at the end of the clip instead.

Since the "focus pull" ended with the focus near the tips of the branches along the bottom, quite a bit of the background branches are out of focus.  The detail crop of the upper right of the frame is actually just barely in the depth of field, but it is easier to see the branches because there are fewer of them.

Do Pentax lenses have a "Pentax look"?  Some people say that it is true.  In this clip, the colours seem softer and a bit creamier, but that could just be the sunlight on that day with the camera pointed in that direction.  I can't tell.

---
*Part 4*

Frame capture:
"Part04-2019-06-04-13h45m34s168.png" [not uploaded]
13,923,116 bytes

Convert to JPEG:
"Part04-2019-06-04-13h45m34s168a-C1.jpg" [not uploaded]
Size: 8,261,654 Bytes

Resize:

*"Part04-2019-06-04-13h45m34s168b-rsz1600-C1.jpg"*


Detail crop:

Start 2180,650
1240 x 930

*"Part04-2019-06-04-13h45m34s168c-Crop01-C1"*


Of the clips that I recorded on the 15th, this was the only one I put out of order in the final short.  I did not want to end with it.  It is also the only clip I recorded with an exposure adjustment.  I have no record of how far off the EV was but I think it might have been EV = +1.3.  I just lightened it until the blossoms looked good overall.  I do not remember if there were any clouds near the sun.  The blue sky retained in the corners was probably just the result of reduced optical transmission ("vignetting").

The SLR Magic 8mm F4 lens was set at F8, which I feel is the only setting it can be used at, and the camera automatic ISO was probably ISO-200.  I do not think I bothered to re-focus after the clip in part 5, so this was probably just "depth of field".  The sun flare is not bad.

---
*Part 5* [clip 58]
- road by Grenadier Pond

Frame capture:
"01-2019-05-22-19h06m37s098.png" [not uploaded]
Size 12,714,522 Bytes

Convert to JPEG:
"01-2019-05-22-19h06m37s098a-C1.jpg" [not uploaded]
Size: 7,193,245 Bytes [PaintShop Pro X9]

Resize:

*"Part05-2019-05-22-19h06m37s098a-rsz1640-C1.jpg"

Test Gamma Correction:*

Curves: [3 points added]
in 5 out 14, in 28 out 63, in 125 out 184

SmartFix
Brightness
Overall 0 [5 Recommended]
Highlights -5
Saturation 5
Focus 30
White balance [yes]
Black 14
White 2

*"Part05-2019-05-22-19h06m37s098b-rsz1640-C2.jpg"*


Detail Crop:

Start 0,520
Size: 1240 x 930

*"Part05-2019-05-22-19h06m37s098c-Crop01-C1.jpg"*

This clip was used without readjustments, and it actually was better than it looks.  I tried adjusting the gamma in the captured frame and shadow detail is quite usable.  That attempt went a bit further than I like and I think I would have preferred a gamma somewhere between the adjustment and the original.  But that is the real reason I did not make it in the first place.  It could take me hours fiddling with it to get it right, and it was already late into the night of the 17th -- my deadline.  I started the upload to YouTube at 23:50 on the 17th and it was not completed until around 00:15 on the 18th, which was more work than I allocated for it.

On the other hand, I am glad I did not alter this clip because I ran into the problem of having people's faces in it.  If people are identifiable, then I need releases, either on paper or at least verbal.  I would rather just not have faces in my videos than take chances.  In this case it was borderline.  If there are few pixels in the faces then they become "generic".  In this case, it was becoming arguable.  But the shadows helped obscure them.  So even if I had the time to adjust the gamma in the clip I might have decided not to bother.


----------



## VidThreeNorth

I was doing some research regarding the sensor in the Yi-M1 (Sony IMX269 sensor) and wandering through the web links I found that apparently the Yi-M1 is available again.

Prices are US $599.99 for the camera in white and both lenses:

YI M1 Mirrorless Digital Camera Pearl White

or $549.99 for the black version:

YI M1 Mirrorless Digital Camera

NOTE:

- Old stock from previous releases is currently still around at prices under US $300 (not sure of the lens packaged).

- Also, there has not been a firmware update since version 3.2 was released in the 2018 Fall, which means the new bug in the 2K video mode is still there, and no further improvements.

- Also, I checked the Website for spare batteries and there are none.


----------



## Braineack

but why would anyone want it?  especially at that price?


----------



## VidThreeNorth

At the $550 - $600 US w/both lenses, it cannot really compete with the Panasonic G7 w/14 - 42mm "Version 2" zoom going for under $500 US.  That much is an easy call.  But the under $300 US kits are not so easy.  If I could get the kit with the 42.5 mm F1.8, I would consider that lens to be worth about $300 US, so the body is essentially free.  A "free" body?  That is actually hard to argue.  The body is not wonderful, but it's not "completely worthless" -- at least not if you already have Micro 4:3 in the first place.  It is the best body I have for adapting manual focus lenses on.  But still, $500 US for the G7 w/the Version 2 zoom is the long run better choice with really strong UHD video capabilities.  If I was really looking for a camera, I'd probably go with the G7 kit.


----------



## n3eg

I just ordered one with kit lens for $150 at Amazon.  We'll see how this works out.  I'll also be comparing the 12-40 lens with the Olympus 14-42 and the Kodak 12-45.  So far, the Kodak has a slight edge.


----------



## VidThreeNorth

You have the Kodak zoom?  Now that is interesting.  It would be great if you could post a few pictures from that one.

I can tell you a bit, generally about the Panasonic and Olympus 14-42 kit zooms:

*First Generation:*

I'll start with the Olympus.  On an optical bench it seemed to be a pretty good lens.  But during testing -- even WITH in body stabilization, some testers found motion blurring.  Some attributed this to "whip" action of the lens assembly. from shutter-shock.  They felt that there might be some "play" in the lens assembly.  I'm not so sure about that.  One thing I found using the OM-D E-M10 body and my Olympus 40-150 4.0 - 5.6 zoom is that when I used it on my monopod, I generally got good sharp pictures.  But I tried a practice set hand-held over the winter.  It was a cloudy day, but not really heavy, and I was probably targeting around 400 - 500 meters.  I think I got around 4 out of 5 motion-blurred, even with image stabilizing ON.  That was terrible.  If other lower cost Olympus bodies were like that, then the lenses might be ok.

NOTE that the E-M10 has a setting to reduce shutter shock, but I have not bothered with it yet.  As I said, I have no problem when I'm using my monopod, with is most of the time.

The first Panasonic kit zoom did not look so good on an optical bench.  It was not outright terrible, but it was borderline mediocre.  There were signs that some of them might have had lens centering issues.  I would guess that this might have been from the OIS lenses not lining up "at rest".

*Second Generation:*

The 2nd generation Olympus seemed to test better than the first generation, but this might have been either partly or wholly the result of a difference in the bodies.

The Panasonic 2nd generation zoom measures much sharper than the first generation.  It is a new lens design with more aspherical lenses (I can't remember whether the 1st generation had any asphericals), and fewer actual lenses.  In generally, one prefers to get the 2nd generation if possible for either brand.

The Yi 12 - 40 is similar in performance to the 1st generation Panasonic.  It is not quite as good as the Panasonic overall, but actually, not that different.  The worst performance is at the wide angle end.  There is heavy barrel distortion which is corrected during processing.  So the corners are stretching pixel data.

On the other hand, when recording UHD, the camera only uses the mid-sensor pixels, so the worst part of the lens is not used.  So it actually is not that bad for UHD video.


----------



## beagle100

VidThreeNorth said:


> *About the "2019 Toronto, High Park, Cherry Blossoms" Video:*
> 
> The camera work was rushed for a few reasons.  First, I only allocated three days to record, edit and upload this project.  Also, for the recordings, I knew that I had to work quickly to avoid the crowds of visitors to the park.  And then there was the weather.  The cloud cover on the first day turned out perfectly while I was recording, but it cleared by the time I ran down the battery on the Yi-M1, leaving harsh contrast and deep black shadows.  Two days later when I returned, it was similar.
> 
> 
> *Part 1* (file 042)
> 
> Frame Cap to PNG:
> "01-2019-05-26-09h34m04s508.png" [not uploaded]
> Size: 12,770,082 Bytes
> 
> Convert to JPEG:
> "01-2019-05-26-09h34m04s508a-C1.jpg" [not uploaded]
> Size: 7,104,546 Bytes
> 
> Resize:
> *"Part01-2019-05-26-09h34m04s508b-rsz1640-C1.jpg"*
> 
> Detail Crop:
> Crop Start:
> 3000,800
> Size 1640 x 1230
> 
> *"Part01-2019-05-26-09h34m04s508c-Crop01-C1.jpg"*
> 
> This "establish" clip is unusual both in composition and in the fact that I actually do not know very much about it.  First, I do not know the focal length, nor the aperture, nor the exposure time.  I picked the location moving the tripod and camera around trying to get the crest of the hill in the picture, and the foreground trees, all forming a window-like appearance.  Then the focal length was adjust to crop the scene, and I did not record it.  The aperture and shutter speed were automatic.  I can guess that the ISO was 200, because that is where it stays for typical daylight exposure.
> 
> I also do not know where it is focussed.  In a situation like this, I have found that the Yi-M1 usually focuses on the background, but on occasion, it picks something near and throws the background out of focus.  When I setup the composition and looked at the focus, it looked sharp all through on the screen, and I accepted it without manually picking a focus spot.  I thought that I would be able to find the focus later, but I have not been able to do so.
> 
> I think that it might have picked the crest of the hill in the foreground.  The bark on the tree to the far right in the detail crop looks particularly good.  Looking at the branches in that tree, some of them also look very good.  The aperture must have been on the small end because even the cherry blossom clusters in the background seem to have some distinct shaping, yet there is noticeable softening past the foreground trees.  Part of the "softness" is caused by the Y'CbCr 4:2:0 chroma sub-sampling and is used in typical video, and that disguises the focus too.
> 
> Was there something about this Panasonic lens that added to the preference to focus in the foreground?  I do not think so, but I cannot say for certain.
> 
> ---
> *Part 2*
> Capture to PNG:
> "01-2019-05-26-10h24m45s856.png" [not uploaded]
> Size: 11,150,185 Bytes
> 
> Convert to JPEG:
> "01-2019-05-26-10h24m45s856a-C1.jpg" [not uploaded]
> Size: 6,256,175 Bytes
> 
> Resize:
> *"Part02-2019-05-26-10h24m45s856b-rsz1640-C1.jpg"*
> 
> Crop:
> *"Part02-2019-05-26-10h24m45s856cCrop01-C1.jpg"*
> 
> The recording situation for this clip was similar to the first, though I adjusted the tripod location based on the start and end of the pan.  Unfortunately, I did not have a good tripod for this project, so it did not turn out as smooth as I would have liked.  I wanted to have as many cherry trees as i could get in the composition at the end of the pan.
> 
> Again, I do not know the focal length, aperture, shutter speed, nor the ISO.  I made the adjustments and then did not take the time to note them.  I think that when this frame was taken, the camera was probably focussed on the main cherry tree that fills a large part of the right side of the image.  If you check the detail crop, the garbage bins in the bottom right are suspiciously sharp, but the grass around the base of the tree is detailed enough to indicate that the tree might have been the real target.  But even the signs past the tree show that the depth of field was allowing a lot of leeway.
> 
> The clouds were clearing quickly and I was lucky to get a set that I felt was perfect.  It is ironic that this 2 min. short is particularly calming and relaxing, but the actual recording was tightly scheduled and rushed.
> 
> ---
> *Part 3*
> 
> "01-2019-05-30-10h11m52s075.png" [not uploaded]
> Size: 11,889,336 Bytes
> 
> Convert to JPEG:
> "01-2019-05-30-10h11m52s075a-C1.jpg" [not uploaded]
> Size: 6,191,561 Bytes
> 
> Resize 1904 x 1080:
> *"Part03-2019-05-30-10h11m52s075b1-rsz1904-C1.jpg"*
> 
> Crop01 from top right
> 1640 x 1230
> *"Part03-2019-05-30-10h11m52s075c1-Crop01-C1.jpg"*
> 
> This part was recorded on May 17, which was the due date.  The original clip I recorded was borderline.  It was taken with the Panasonic lens and the autofocus could be seen "seeking" a bit.  The focus was overall a good compromise "hyper focus", but the closest branches sometimes looked a bit soft.  The clip was good enough, but I wanted to see if I could do better.  So I went back with my Pentax 50mm F2.0.  I tried a "focus pull" but again, my tripod was inadequate and merely touching the lens caused visible shaking, so I used the extra time at the end of the clip instead.
> 
> Since the "focus pull" ended with the focus near the tips of the branches along the bottom, quite a bit of the background branches are out of focus.  The detail crop of the upper right of the frame is actually just barely in the depth of field, but it is easier to see the branches because there are fewer of them.
> 
> Do Pentax lenses have a "Pentax look"?  Some people say that it is true.  In this clip, the colours seem softer and a bit creamier, but that could just be the sunlight on that day with the camera pointed in that direction.  I can't tell.
> 
> ---
> *Part 4*
> 
> Frame capture:
> "Part04-2019-06-04-13h45m34s168.png" [not uploaded]
> 13,923,116 bytes
> 
> Convert to JPEG:
> "Part04-2019-06-04-13h45m34s168a-C1.jpg" [not uploaded]
> Size: 8,261,654 Bytes
> 
> Resize:
> 
> *"Part04-2019-06-04-13h45m34s168b-rsz1600-C1.jpg"*
> 
> 
> Detail crop:
> 
> Start 2180,650
> 1240 x 930
> 
> *"Part04-2019-06-04-13h45m34s168c-Crop01-C1"*
> 
> 
> Of the clips that I recorded on the 15th, this was the only one I put out of order in the final short.  I did not want to end with it.  It is also the only clip I recorded with an exposure adjustment.  I have no record of how far off the EV was but I think it might have been EV = +1.3.  I just lightened it until the blossoms looked good overall.  I do not remember if there were any clouds near the sun.  The blue sky retained in the corners was probably just the result of reduced optical transmission ("vignetting").
> 
> The SLR Magic 8mm F4 lens was set at F8, which I feel is the only setting it can be used at, and the camera automatic ISO was probably ISO-200.  I do not think I bothered to re-focus after the clip in part 5, so this was probably just "depth of field".  The sun flare is not bad.
> 
> ---
> *Part 5* [clip 58]
> - road by Grenadier Pond
> 
> Frame capture:
> "01-2019-05-22-19h06m37s098.png" [not uploaded]
> Size 12,714,522 Bytes
> 
> Convert to JPEG:
> "01-2019-05-22-19h06m37s098a-C1.jpg" [not uploaded]
> Size: 7,193,245 Bytes [PaintShop Pro X9]
> 
> Resize:
> 
> *"Part05-2019-05-22-19h06m37s098a-rsz1640-C1.jpg"
> 
> Test Gamma Correction:*
> 
> Curves: [3 points added]
> in 5 out 14, in 28 out 63, in 125 out 184
> 
> SmartFix
> Brightness
> Overall 0 [5 Recommended]
> Highlights -5
> Saturation 5
> Focus 30
> White balance [yes]
> Black 14
> White 2
> 
> *"Part05-2019-05-22-19h06m37s098b-rsz1640-C2.jpg"*
> 
> 
> Detail Crop:
> 
> Start 0,520
> Size: 1240 x 930
> 
> *"Part05-2019-05-22-19h06m37s098c-Crop01-C1.jpg"*
> 
> This clip was used without readjustments, and it actually was better than it looks.  I tried adjusting the gamma in the captured frame and shadow detail is quite usable.  That attempt went a bit further than I like and I think I would have preferred a gamma somewhere between the adjustment and the original.  But that is the real reason I did not make it in the first place.  It could take me hours fiddling with it to get it right, and it was already late into the night of the 17th -- my deadline.  I started the upload to YouTube at 23:50 on the 17th and it was not completed until around 00:15 on the 18th, which was more work than I allocated for it.
> 
> On the other hand, I am glad I did not alter this clip because I ran into the problem of having people's faces in it.  If people are identifiable, then I need releases, either on paper or at least verbal.  I would rather just not have faces in my videos than take chances.  In this case it was borderline.  If there are few pixels in the faces then they become "generic".  In this case, it was becoming arguable.  But the shadows helped obscure them.  So even if I had the time to adjust the gamma in the clip I might have decided not to bother.



OK, so after a couple of years you still like the Chinese camera ....
*www.flickr.com/photos/mmirrorless*


----------



## NathanielGoodtimes

I just picked it up for about 200 with both lenses. This is my first step pasted a point and shoot and I am loving it.

Sent from my SM-G950U using Tapatalk


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## Original katomi

I saw the op and had a Pink Floyd moment, Hay teacher......


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## NathanielGoodtimes

NathanielGoodtimes said:


> I just picked it up for about 200 with both lenses. This is my first step pasted a point and shoot and I am loving it.
> 
> Sent from my SM-G950U using Tapatalk


Here are some pics so far
All untouched jpgs







Sent from my SM-G950U using Tapatalk


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## VidThreeNorth

NathanielGoodtimes said:


> I just picked it up for about 200 with both lenses. This is my first step pasted a point and shoot and I am loving it.
> . . .



It looks like you're doing well so far.  As I wrote above, the 42.5mm is a very good lens.  Unfortunately, I have never seen batteries sold separately for this camera.  If you ever see one than let us know.


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## kazanunda

I've been using Yi M1 for about a year now and I can agree that it is a really nice camera for manual lenses.

Though it does have it's quirks. For example sometimes if I shoot it in portrait orientation, the bottom side of the image will get darkened as if a gradient was pasted over it (bottom side of the sensor when the camera is in landscape orientation). The weirdest part is that it's inconsistent, it doesnt happen all the time. I have yet to test it with different lenses and the same lenses on the spare Yi, just curious if you have had the same issue?


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## VidThreeNorth

I haven't seen anything like that happen on my camera.  If you can upload an example or two I might have an idea about it.


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## kazanunda

Spoiler: image












I have a couple other examples of it, but I cant seem to find them at the moment. The left side is heavily darkened.


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## VidThreeNorth

That looks like some kind of shutter failure.  Unfortunately, I have no detailed information about how these new shutters work.  Is this happening during rapid sequence "burst" shooting or is it happening during single shots with a time gap?


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## kazanunda

During single shots with a time gap, I rarely do bursts because of it's limited buffer. But wouldn't shutter sticking leave a straight break line where it got stuck passing over the sensor, instead of a gradient?

Edit I have tested the spare unused M1 today with the 28mm kamlan. I suspect it may be lens related as the images showed the exact same gradient. Curiously, it only happens in portrait mode and the bottom side is darkened regardless of how I rotate it in the portrait mode. I couldnt find this issue on portrait shots with the kamlan 50mm f1.1 mark2, so at this point I am fairly certain its lens related.


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## VidThreeNorth

I have no real information about how modern shutters work, so I was just playing with an idea.  From what descriptions I have seen, it seems like they are powered by variations on "linear motor" technology which is similar to the top quality lens focussing drives.  It would take a surge of power to get the blades up to speed, and that would take a capacitor of some kind.  I was thinking that the first shutter curtain capacitor might not be charging fully, so that it might slow down by the end of the run. 

If the second blade is moving faster then it could catch up to the first blade, reducing the exposure.

I don't know that lens.  Is it M43 mount?  If the aperture is actually being opened or closed by the camera, then the aperture might simply be too slow.  Are other lenses working properly?


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## kazanunda

Other lenses are working fine.

Kamlan only makes fully manual lenses.

Recently got a 180mm f2.8 zeiss, so that will be interesting on MFT, just need to wait for the adapter to arrive.


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## VidThreeNorth

Since it is a fully manual lens then neither the shutter nor the aperture should have any such problem.  I can't see any answer to it.  Since all the other lenses are working, then my "absolutely brilliant" suggestion is: "just don't use that lens."


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## mmsumulong

VidThreeNorth said:


> NathanielGoodtimes said:
> 
> 
> 
> I just picked it up for about 200 with both lenses. This is my first step pasted a point and shoot and I am loving it.
> . . .
> 
> 
> 
> 
> It looks like you're doing well so far.  As I wrote above, the 42.5mm is a very good lens.  Unfortunately, I have never seen batteries sold separately for this camera.  If you ever see one than let us know.
Click to expand...


https://www.amazon.com/gp/product/B07VNRVX6H/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I purchased this myself and is slightly better than the OEM battery. Do note that this is a cheap camera but workable as a secondary/backup camera or something to toy around for experienced users. But is still fine for novices. There are obviously better  cameras than this. But the batteries work great. And the charger is a plus! [edited]


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## kazanunda

Regarding obtaining batteries in europe, I can recommend electropapa from germany: Li-Ion-battery - 900mAh (8.8V) - for camera, digicam, DSLR replaces XiaoYi BXM-10 - Electropapa

To be honest they arent as good as original batteries, but they work well enough. Biggest issue in getting them from china is that they arent being sold with chargers at all. And solo batteries cant be shipped by air.

I also heard some people recommending kodak batteries because of similar shape and size. The indents are in the wrong corners and the terminals on the battery are reversed, so it wont work.


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## VidThreeNorth

Much thanks guys!  Unfortunately, the Amazon vendor linked will not ship to Canada, so I will have to check further.  Maybe the Electropapa site will.  I'll look into it later.


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## mmsumulong

VidThreeNorth said:


> Much thanks guys!  Unfortunately, the Amazon vendor linked will not ship to Canada, so I will have to check further.  Maybe the Electropapa site will.  I'll look into it later.



The ebay seller(s) ship(s) worldwide.  But loses out on Amazon.  But again I have purchased these on Amazon and they are rated better than the OEM and the bundled charger is a boon too.

DSTE 3PCS BXM-10 BXM10 Rechargeable Li-ion Battery for XIAOYI M1  | eBay

DSTE US Plug Battery Charger with Car Adapter for XiaoYi BXM-10 Camera Battery  | eBay


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## VidThreeNorth

Much thanks again.  I ordered the charger set from the Amazon link in #69 and it arrived a couple of weeks ago.  The batteries and charger are all working.  It was all "just in time." My original battery was getting thick, meaning that the internal battery was deteriorating and not safe.  I have recently bought a Panasonic G85 which will become my main "4K" video camera for now.  That means I will mainly be using the Yi-M1 for still pictures in the future.  Those, along with my Panasonic GF3 form the core of my M43 system.

The following link points to the topic for my "Autumn" video.  This will probably be the last video that post that came completely from the Yi-M1.  I was particularly happy with how the colours turned out in it.

"20101020 Toronto Autumn"
20101020 Toronto, Autumn


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## VidThreeNorth

I have finally gotten around to buying a standard colour card.  I bought a Datacolor "SpyderCheckr 24".  I already had an Elvid slate which has a partial set of colours.  Combining the two gives me a good range.  Apparently, Datacolor also has a free downloadable program to use with their colour card.  I had a method of evaluating colours in mind, but I will probably download and install that program as well.

I spent most of today recording videos for evaluation from my Yi-M1 and my Panasonic G85.  These are frames captured from some of those videos.

Conditions:  This was a morning file set (around 9:30-ish) on a clear day.  I was careful not to locate the card in shadow, but due to the angle, the card did reflect light more directly towards the Panasonic.  The cameras were located on my 3D bar and were about 3' away from the card.  The card is sitting on top of the Elvid slate to keep it off the grass.  The lens on the Yi-M1 is my Panasonic 12-42 F3.5-5.6 and the lens on the G85 is the 12-60 F3.5-5.6.  Focal lengths were around 30-35mm.  Exposure settings were not recorded.  Both cameras were set to Auto exposure and Auto white balance.  ISO should have been 200 for both.  Exposure compensations are noted for each clip.  I tested EV = +0.0 for each of the profiles that I was interested in, and for some I also tested EV = -1.0 and sometimes also EV = +1.0, all according to my current interests.  I am not uploading captures from all the files I made.  These are just the ones I think are most interesting.

NOTE:  I might post evaluations later or I might not.  There are "how-to" videos and web pages that teach evaluation methods, so anyone can do their own.  You don't need my  comments.

_[2020-04-26 15:13]
The Panasonic G85 files have been uploaded to "G85 w/12-60mm F3.5-5.6 lens"_

[All JPEGs compressed level 1]
"YiM1-P4250002-Standard-ev0_0-12h42m50s970.jpg"
"YiM1-P4250005-Portrait-ev0_0-12h55m21s883.jpg"
"YiM1-P4250006-Portrait-evMinus1_0-13h09m23s876.jpg"
"YiM1-P4250009-Vivid-ev0_0-15h00m51s788.jpg"


----------



## VidThreeNorth

*YiM1, Panasonic 12-42 F3.5-5.6 zoom (version 1)*

Before I got the colour checking card, I did not have a really accurate way of evaluating how my cameras were treating exposure.  As time went on, I was developing a general idea, but it was a slow process of trial and error.  My previous conclusion was that the contrast and "dynamic range" of the three colour profiles of the Yi-M1 were very close.  I did notice that the "Portrait" seemed to give a bit more shadow detail, so I thought it probably had a bit more dynamic range.  I had little experience at all with the "Vivid" profile because it seemed too saturated for what I was recording.  Now that I have the colour checking card, the first thing I wanted to find out was what differences if any there were.

I used the pixel reading ability of Corel Paint Shop Pro to read five pixels in each of the six grey squares of the captures ("Standard" w/EV = +0.0 and "Portrait" w/EV = +0.0".  For convenience, I will call these colours  (in order from darkest to lightest) "Black", "Black + 1", "Black + 2", "White - 2", "White - 1" and "White".


Graph Data:

The following are the brightness "[luma"] values in 8-bit form for some of the sample images:

[All JPEGs compressed level 1]

"YiM1-P4250002-Standard-ev0_0-12h42m50s970.jpg"

"Black" = 17.5 (below 20)
"Black + 1" = 60.9
"Black + 2" = 130.2
"White - 2" = 184.9
"White - 1" = 223.8
"White" = 246.0

"YiM1-P4250005-Portrait-ev0_0-12h55m21s883.jpg"

"Black" = 30.8
"Black + 1" = 78.2
"Black + 2" = 144.2
"White - 2" = 198.3
"White - 1" = 232.0
"White" = 254.4 (clipped)


"YiM1-P4250009-Vivid-ev0_0-15h00m51s788"

"Black" = 13.6 (below 20)
"Black + 1" = 59.6
"Black + 2" = 132.6
"White - 2" = 193.6
"White - 1" = 234.1
"White" = 254.8 (clipped)


"G85-00010-Standard-ev0_0-13h26m54s730"

"Black" = 54.9
"Black + 1" = 104.5
"Black + 2" = 163.0
"White - 2" = 207.3
"White - 1" = 235.3
"White" = 253.5 (clipped)

_[2020-05-09 19:41 reformatted the above for consistency]_

*Special Cases:*

There are three "special cases" I should explain.  All have to do with the "White" or "Black" values.  The far limit values are "0" and "255"  If even 1 of the values of red, green or blue component values for any of the pixels tested is equal to either "0" or "255", then I have marked the resulting Luma value as "clipped".  Since I only tested five pixels for each colour, it can be assumed that more pixels had such values.  For such a case, I would prefer to adjust my exposure to better "contain" the exposure of that brightness level if it can be practically done.  So if I see clipping, then I will probably adjust to eliminate it.

The "under 20" values are not as urgent.  "Under 20" is a broadcast standard for "black"  That is to say that any value under "20" can be presumed to be "black" for the purposes of North American television.  That is all it means.  It is commonly called "legal black", but that is a misconception.  There is no "law" being violated.  However, values below 20 can be "noisier" and are thus less reliable.  But there is no guarantee that a value higher than 20 will be free of noise.  One needs to study one's camera(s) to know how much of "under 20" can be recovered in post.

*The Graph:*

I graphed some of the values as "reciprocity curves" and there are a few things that can be said about the results.

First, the contrast situation was a bit worst than I thought -- not much, but definiitely worse.  The reciprocity curves for the Yi-M1 are almost identical.  Yes, there is slightly less contrast in "Portrait" profile, but only around a half stop less than the "Standard" profile.  The exposure of of the "Portrait" profile appears to be about 1/3 stop lighter than "Standard".  This accounts for part of the increased shadow detail.  Unfortunately, to make use of the full dynamic range in "Portrait", I would need to expose at at about "EV = -1/3", which gives up some of that shadow detail.

In the "Standard" profile, the "Black" sample brightness is entirely below 20, which is "legal black".  It was not clipped, but recovery is unreliable.  I have recovered shadows in some cases, but my experience confirms this limitation.

The contrast for "Vivid" is even worse than "Standard".  I did not bother to graph it.  Now that I know how limited its dynamic range is, I don't intend to use it again.

The "G85 Standard" profile is included as a control (for comparison).

Finally, to find a single number value to compare the reciprocity for each profile I subtracted the "black + 1" value from the "white - 1" value.  For these values, the lower results indicate less contrast.  It is not necessarily true that one always wants less contrast, but for most of what I do, that would be my general goal.

 In fact, I probably will not even use the G85 "Standard" profile very much.  The G85 has profiles with even less contrast, which I will probably use more often.  I doubt if I will use the Yi-M1 for video much in the future, but if I do, from now on, I will probably only use the "Portrait" profile.  Since I use the "Histogram" function on that camera when chosing my exposure, I generally set it to "protect" my highlights that way.  If I didn't, then I would probably try to reduce the exposure by "EV = -1/3" from now on.

Yi-M1 Standard 223.8 - 60.9 = 162.9
Yi-M1 Portrait 232.0 - 78.2 = 153.8
Yi-M1 Vivid 234.1 - 59.6 = 174.5
G85 Standard 235.3 - 104.5 = 130.8


----------



## VidThreeNorth

*Yi-M1 4K Portrait Video Profile:*

I thought that I had finished my analysis of the Yi-M1 video modes but over the years I have learned that it often pays to take do a bit more than what should be enough.  In this case there was a pay-off.

All the tests I have reported above were using recordings at 1080P (30 fps, and with digital stabilizing "ON").  I did this because I assumed that this would be my general setting for future video recording with this body.  But after I completed the test sets I made a second "control pair" with the Panasonic G85.  That means I recorded using the two cameras at the same time.  I did this because a lot of time had passed since the original control pair and the lighting had changed a bit.  I did not think it had changed enough to make a difference to my findings, but the point of doing the second control pair is to make sure that this is true.

However, just to make it a more valuable test, I changed the settings of both cameras.  On the G85 I decreased the exposure by 1 stop, and on the Yi-M1 I decided to set it to "Portrait" and EV - +0.0 again, but at UHD ("4K").  I expected the results to be essentially the same as the 1080P recording.


*"P4250011.MP4"*
- 4K, Portrait EV = +0.0

File: "YiM1-P4250011-4K-Portrait-ev0_0-14h42m19s888.png"

"Black" sample: Luma = 52.1
"Black + 1" sample: Luma = 92.6
"Black + 2" sample: Luma = 151.3
"White - 2" sample: Luma = 194.4
"White - 1" sample: Luma = 223.0
"White" sample: Luma = 238.0

Contrast: ("Black + 1" - "White - 1")
 223.0 - 92.6 = 130.4

In general, the contrast I calculated is significantly less than any of the Yi-M1's 1080P settings and close to the G85's "Standard" profile.  Is there any reason for this in my test procedure?  Possibly.  When I switched from 1080P and Electronic Stabilizing ON to 4K (there is no stabilizing option for 4K) the crop changed, and so I zoomed out.  When I did this, I actually matched the effective crop of the G85 almost perfectly.  The only difference is that the Yi-M1 was pointed downward a bit.  But the proportion of the background is closer than it was when I was recording 1080P.  The question becomes whether there is any "dynamic range optimizing" going on.  The Yi-M1 does not mention this, however, it is not an unusual function.  One advantage of this function is that during video recording, the main subject is less likely to change exposure.  It would be nice if this were mentioned in the instruction manual, but the Yi-M1 manual is sparse in general.

There are a couple of tentative conclusions I can make.  First, just from this much testing, it seems like the best video recording for my personal general use might be "4K - Portrait".  If there is "dynamic range optimizing" going on, then the "4K" might actually not make any real difference to the dynamic range, but until I do further testing, I will assume that the "4K" is making a difference.  And the second conclusion is the obvious "I should do more testing someday."

Having said this, I have some mixed feelings.  First, aside from the high contrast and lack of dynamic range, I actually like the "Standard" colour rendition of the Yi-M1.  The main difference of the "Portrait" profile is that saturation is reduced.  So if I record in "Portrait" from now on, I will have to increase the saturation in post.  In the long run, it should not be a problem, but when I am evaluating what I have recorded, I generally just see my clips in VLC which does not have that kind of tuning ability.  That is going to make it a bit harder for me to evaluate what I have.  On the other hand, it won't be any worse than recording on the G85 in "CineLikeD" which is even "worse".

Second, it means that really, I am probably going to stick to "4K" video recording on the Yi-M1, with all the drawbacks of storage usage, and the fact that my "main" computer cannot be used to preview "4K" video -- I can only view it on my "editing" computer, which I usually leave "Off", or in "Sleep" mode.

Even with the better dynamic range of "4K Portrait" profile, the Yi-M1 is still really not going to be a great "sunny day" camcorder.  It will still be best for overcast days, but I might not have to re-tool the gamma quite as much.

*About The Sample Frame:*

I chopped up the 4K sample frame into four parts.  For this report only parts "A" and "B" (the top half of the overall frame) are used, but I have uploaded the rest in case you want to compare the colours against the Full HD frame.

You might notice that these pieces are 1920 * 1089.  The actual format of the Yi-M1's UHD files is 3840 * 2178.  The file defines the target format as 3840 * 2160 and the displaying device does the re-scaling.  It is actually fairly common.


----------



## VidThreeNorth

*Yongnuo M43 42.5mm, F1.7, Version 1 Lens*

This is going to be a very short post.  I recently bought this lens (new), hoping that I could use it on all my Micro 4/3 camera bodies.  Unfortunately, so far, the Yi-M1 has turned out to be the only body I own that it does not work on.  Nothing works.  It does not focus and the aperture does not adjust.  There is a new Version 2 of this lens, but I have no idea if it works.  We will just have to wait for someone else to try it.

About why it does not work:  When you mount a fully working Micro 4/3 lens on most bodies, it has to be pressed so that the flange on the lens touches the flange on the body before it can be twisted into place.  The reason for this is because the electrical contacts in the body push against the contact plate on the lens, in order to ensure that they touch the electrical pads.  When I mount the Yongnuo lens, it seems to drop into the lens cavity, only being stopped by the release pin.  In other words, it appears that the electrical contacts are not close enough to the body to ensure that the pins in the body are actually making contact.  There might be other problems or not, but that much would be the first thing to fix.  But I will not actually try to fix it myself.  It is working on my Panasonic bodies, so I am going to simply use it on that body.

Since I do not intend to attempt any kind of fix, it is unlikely that I will post anything more about this combination in the future.


----------



## VidThreeNorth

Lens: *Panasonic H-FS014042 14-42 F3.5-5.6*

*"P3260013.JPG" *(Source picture not posted)
Yi-M1 "Portrait" mode JPEG
Size 5,042,326 Bytes
Created March 26, 2021, 13:48:58

Win 8.1, Partial Properties
Program name ASDK-00142
Dimensions 5184x 3888
Bit depth 24
Resolution unit 2
Color representation Uncalibrated (Adobe RGB)
F-stop f/5.6
Exposure time 1/80 sec
ISO speed ISO-640
Exposure bias 0 step
Focal length 42 mm
Max aperture 4.98
Metering mode Center Weighted Average
35mm focal length 84
White balance Auto
EXIF 0230

- the following files based on the camera JPG using Coral Paintshop Pro X9

*"P3260013a-rsz1920-C1.JPG"*
- resized to 1920, no other adjustments

*"P3260013b-Crop1920-C1.JPG"*
- detail crop, no other adjustments
- Crop start 1150 x 1300


This picture was a result of casual curiosity resulting from my previous test picture of the strawberries using the Yongnuo 42.5mm lens on the Panasonic G85.  On the spur of the moment I decided to see how it would turn out using my Panasonic H-FS014042 14-42 F3.5 - 5.6 kit zoom.  This is the original series zoom and not the slightly better second series zoom.

The picture was taken on my Yi-M1, because this was the body that the Yongnuo was supposed to work on -- this is why I bought it.  So you can think of this as the picture taking capability that it was supposed to "beat".  Or more correctly, it is one of my lenses it needed to "beat" to be useful.  Since the Yongnuo does not work on this camera, it is fair that I have taken this on the 20MP Yi-M1 while the only test picture I have posted for the Yongnuo was take on the 16MP Panasonic G85.  That is to say, that for me, the only reason it cannot take a 20MP picture is because it failed to work on this camera.

In theory, if the pictures had been taken on the same 20MP body, then the level of detail would have had that starting point, but the result is that the Yongnuo simply could not do it.Beyond that, although it is hard to tell with such dis-similar pictures, the Panasonic does look a bit sharper.  Anyway, eventually, when I get the time, I will eventually get around to doing more "scientifically valid" testing.  But for now, this answers some of my curiosity.


----------

