# Exposing to the right



## Eagle74 (Feb 5, 2014)

Hi everyone,

I need some expert advice. I want to shoot in manual as much as possible but zero'ing out the meter often gives unexpected exposures.

As a newbie shooting Raw and post processing should I be checking the histogram and adjusting until I am at the edge of clipping the hightlights?

I read somewhere on the "internets" that this is a good idea, but I simply don't know enough to know if this will be a good practice to adopt.


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## SCraig (Feb 5, 2014)

If all you are doing is picking a scene, zeroing the meter, and shooting then you might as well just shoot in auto mode.  All you are doing is setting the dials the same way the camera would, so what's the difference?  If you are going to shoot in manual mode, which in my personal opinion is frequently overrated, then the goal is to UNDERSTAND exposure and not just mimic what the camera picks out.

Meter on something that will correspond to neutral gray in direct sunlight, set that as your manual exposure value, and then compensate when the light changes or you point in a different direction.  Crushed stone, light-colored asphalt, grass, even the palm of your hand will work.  LOOK at the light.  See what the differences are.  Then compensate for them; is it brighter or dimmer, is the subject in shade instead of direct sunlight?  In time you'll understand WHY the adjustments do what they do.

As to exposing to the right, read This for a good understanding.


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## apaflo (Feb 5, 2014)

Eagle74 said:


> Hi everyone,
> 
> I need some expert advice. I want to shoot in manual as much as possible but zero'ing out the meter often gives unexpected exposures.
> 
> ...



The "right" way is to learn the advantages of each exposure mode and then pick the appropriate mode as required for whatever you are doing.

 That said, the most common configuration that I use is Manual Exposure, with AutoISO, and then fine tuned with whatever amount of Exposure Compensation is required.  Generally I use a center weighted light meter setting.

None of that is ever cast in concrete and for any given shot or for an entire job I may well switch to something else.  (I don't think I've ever really used a "Programmed Mode" for other than testing.  I also never use Matrix Metering or Active D Lighting, which are Nikon specific light metering variations.)

So what's that all mean???  I set Aperture and Shutter Speed for artistic effects.  I let the camera adjust ISO to get an appropriate image, though I might "recalibrate" the light meter a little up or down using Exposure Compensation.  This absolutely invovles monitoring the camera's Blinking Highlight display and the RGB histograms.  Maybe not for every shot, but absolutely for the first few shots until I've got it "right", and every now and then or anytime the light changes to make sure things stay "right".


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## Eagle74 (Feb 5, 2014)

You guys who can just pick something in a scene to meter off of seem like Camera Jedi's to me..lol. 

This is good stuff.

SCraig- Thank you for that link and your advice, I have Bryan Peterson's  "Understanding Exposure" on the way. Seems like there is more to know than just zero'ing out the meter. And that link you provided is Gold!

Apaflo- I just started experiment with Auto-Iso and It works well. I set it to maximum 1600 indoors and the images look great, well..as far as noise goes they look great...composition now that's another story!


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## apaflo (Feb 5, 2014)

> composition now that's another story!



Here's a link about composition for you:

"Entropy and Art" by Rudolf Arnheim

It's about the philosophy, not the specifics.  And it isn't even specific to photography, but applies to any visual art.  Worse, Arnheim isn't exactly an easy read (he emigrated to the US from Germany, and was a classically trained psychologist before that)

"When nothing superfluous is included and nothing indispensable left out, 
one can understand the interrelation of the whole and its parts,
as well as the hierarchic scale of importance and power 
by which some structural features are dominant, others subordinate."

Rudolf Arnheim (1904-2007) had a very profound effect on the world of art during his lifetime. If you can understand composition in the terms of the above quote and implement it in photography, that will be your "another story".


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## KmH (Feb 5, 2014)

it helps a great deal if you understand metering - Understanding Camera Metering and Exposure


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## ShootRaw (Feb 5, 2014)

Shooting manual is not over-rated..It is the most accurate way to shoot once you understand it..


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## bratkinson (Feb 6, 2014)

ShootRaw said:


> Shooting manual is not over-rated. It is the most accurate way to shoot once you understand it..



There should be emphasis on the 'once you understand it' part of the statement. But I'm also of the camp on the side of manual IS overrated.

It seems to me that manual is overrated by inexperienced photographers erroneously believing it is 'the perfect way' for all photography. All too often, we see threads on this forum and others asking 'what settings do I use for...'. And, as always, there are NO magic 'settings to use for...' that will always work. Not even the Sunny 16 rule will work unfailingly on bright sunny daysshooting into a shadow, or backlit, for example. Without an understanding of WHY a particular combination of ISO, shutter speed and aperture provides a specific result, one can only blindly try to get some combination that gives decent results under those specific lighting conditions. &#12288;

While its a goal to shoot as the professionals do, going from "A" to "M" is considerably more difficult than simply turning the little wheel on the top left. In my learning curve to go from A to M I spent a lot of time shooting in P, Av and Tv. Too often, some decide that manual is the silver bullet that will make every picture they take perfectly exposed, perfectly sharp, perfect contrast, perfect saturation, etc. It is. But ONLY if one knows what are the benefits and consequences of every exposure adjustment they make. Granted, failure is a great teacher. But having hundreds of overexposed, underexposed, or blurred pictures caused by trying to shoot everything in manual mode can ruin a vacation, or a family wedding, etc. By the wayon my upcoming vacation in May, I expect to shoot mostly in Auto mode! &#12288;

Manual is also overrated and used as a snob tool by those who purport to use it 100% of the time or stating its the ONLY way to shoot. Its akin to saying that they only drive Ferraris and everyone else is beneath them. I drive a Chrysler. I guess that makes me a loser in photography as well as choice of cars.​


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## Gavjenks (Feb 6, 2014)

In my opinion, manual is pretty much only good for studio shoots, where the lighting stays the same for dozens of shots in a row. Simply as a way of stopping the camera from messing with stuff.

Yeah the meter is often wrong, but you can correct for that just as easily with exposure compensation in any other "Creative" mode as you can in manual, and for those times when you don't need correction, it's faster and does more of the tedious math for you.

But I digress from the real question being asked.  "Exposing to the right" is a concept that cuts across any single shooting mode. You can ETTR in manual or aperture priority, or whatever. And yes, it is often a good idea. _Always _a good idea, in fact, if you have the time to do it, and if you don't have weird artistic goals for the shoot.  But it does take awhile to do constantly, and requires more than one shot. So you really shouldn't rely on it as a 100% of the time, this-is-all-I-do sort of thing, because you'll miss any brief momentary shots, and you will lower your output and harmfully distract your cognitive resources at times when the action is fast and furious.


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## ShootRaw (Feb 6, 2014)

It is quite the opposite^^^Manual is more important outside because light is always changing..So adjusting it manually will be more accurate ...
Now for events, A-priority with exposure compensation is a norm...


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## bribrius (Feb 6, 2014)

I almost always try to use manual mode. Auto is like cheating on a test. Plus I heard once that they made auto mode to try to mimick great photographers adjustments. Key I suppose is auto TRIES to mimmick. That means auto isn't as good as great photography or photgraphers but second best.
who wants to come in second place or second best? 

plus honestly, I don't know how the hell you people are using auto mode. I try to and a good portion of the pics I take in auto come out like crap. I have to use manual sometimes. like I have no choice. lower shutter drop iso notch up exposure lower aperature. I dunno what you would do in auto in some cases. Do you just take the picture and then say "damn, it didn't work" and give up?
My biggest problem however, seems to be I forget to change crap back. Pull the camera out again, take a pic. "what the hell????"
Then  I have restore back to orginal settings. Other thing is modes. shutter app or different landscapes. My dam camera only allows you to adjust the ap and shutter so much. So spin down trying to go to the lower and the thing wont go beneath f4.2 or something. wth? oh. mode??? So I get annoyed in modes and go back to manual. Another reason. I hate not being able to adjust things where I want. But im still learning so...............
But auto, go outside at night or dusk. put it in auto. take a pic,. crap. that didn't work. okay, put it in landscape mode, take a pic. crap. that didn't work. okay. put it in night landscape mode. take a pic. crap. that didn't work. okay. put it in automatic scene selector. take a pic. crap. that didn't work.
okay. hell with this. time to try out manual again.

I just started trying to get used to manual to save myself the headache....
But then... okay. try to keep low iso . take pic. wth. that didn't work. lower ap. take pic what the hell? blurry. increase shutter take a pic. wth? dark. lower shutter, raise iso a notch. bring ap up . crap... almost. better... lower app again. take a pic. crap.. too far.. raise ap slow shutter .. finally... FINALLY...
And .. no ****...
I just did it. That mofo came out...
unless you play with zoom or something then that throw it off. 
exposure compensation manual meter click okay?  yes. usually works . I do it sometimes? sometimes just think"oh its dim" and click it up a couple?
And a thousand times later... 
maybe you get better at manual. Im better than I was, It doesn't take fifty tries anymore at least....
im still learning though.


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## manaheim (Feb 6, 2014)

My suggestion to you... as a newbie... is to put your camera in aperture mode, possibly program mode (not Auto), and just worry about your compositions.

Shoot in manual when you realize that shooting in an automatic mode failed you.

Photography, and the artistry of photography, are INSANELY steep learning curves as it is.  The last thing you need to do is overcomplicate them by throwing away perfectly useful tools that are available on your camera on day one.


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## apaflo (Feb 6, 2014)

ShootRaw said:


> It is quite the opposite^^^Manual is more important outside because light is always changing..So adjusting it manually will be more accurate ...
> Now for events, A-priority with exposure compensation is a norm...



The idea that manual exposure produces a more accurate result is incorrect.  Whether the camera is configured manually or automatically the accuracy depends on how accurate the light meter is.  The same light meter is used for manual exposure as for automatic exposure!  In fact, the camera can autormatically read the meter and set exposure with finer granularity than can be done manually, though the difference is insignificant.

With either Manual Exposure mode or one of the auto modes the meter can be offset using some form of Exposure Compensation.  It all works out to exactly the same *accuracy* either way.

What might be different is either the ease with which an accurate setting is perceived or obtained and how quickly it is done.  That might well be easier and faster using Manual Exposure mode for some people and might just as well be faster for some others using an Auto Exposure mode. (To be very honest, the only time Manual Exposure is faster or easier is when you *don't* understand how to decide what is needed and set it!)

It is correct that straight Manual Exposure mode is more likely to be useful in the studio than not.  Set once, and no change is needed unless the lighting is changed.  Auto Exposure means making sure what you are measuring is the same every single time, and even a minor change in the framing of a scene will change what is measured.  The result, for precise exposure, is tedious work unless Manual Exposure is used.

Outdoors however, the same might apply for some types of work, but the lighting is not totally under the control of the photographer and that "tedious work" is necessary for every significant time interval anyway.

 It is pure nonsense when people make statements such as Shutter Priority is best 90% of the time, or the same about Aperture Priority or Manual Mode.  That might well be true for their style, their talent, and/or their work.  It will absolutely vary with different photographers.

The only valid way to approach which mode is to learn them all and be able to choose the right one and know how to use it.  For example, some events might well work best using Aperture Priority because  subject isolation is the most significant artistic effect for those particular images.  That would be true if the subjects being photographed are not moving in a way that needs to be accounted for.  Weddings, birthday parties, and other social events are examples.  Sporting events are different, and Shutter Priority is commonly more important because subjects need to be "frozen" in just the right amount!  Some motion blur, but not too much, requires a very specific shutter speed.

 And often enough it is far better to let ISO float using AutoISO while the actual exposure (shutter speed and aperture) are *both* set manually for artistic effect.

In any case, all of these exposure modes are only as accurate as the light meter.  They are only as easy as how well they are understood.  And each of them is best in some circumstances and not appropriate in others.


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## bribrius (Feb 6, 2014)

manaheim said:


> My suggestion to you... as a newbie... is to put your camera in aperture mode, possibly program mode (not Auto), and just worry about your compositions.
> 
> Shoot in manual when you realize that shooting in an automatic mode failed you.
> 
> Photography, and the artistry of photography, are INSANELY steep learning curves as it is. The last thing you need to do is overcomplicate them by throwing away perfectly useful tools that are available on your camera on day one.


that's THE THING. the twenty or so modes confuse me more than being in manual. :mrgreen:


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## TCampbell (Feb 6, 2014)

Manual is only more accurate if you use an incident light meter to take your meter reading and dial in the exposure based on that and not based on the in-camera meter -- and especially if you're taking multiple meter readings (highlight readings, shadow readings) and then using an exposure which does not clip or blow the range of the camera.  You could put your camera into spot metering mode then look for the brightest point and darkest point you can find in the scene, meter those separately, then find the middle exposure -- although matrix or evaluative metering mode will try to do this for you anyway.

Otherwise consider this:

You activate the meter in your camera while on Manual mode.  You see an arrow through the viewfinder which indicates if you are over-exposed or under-exposed.  You adjust ISO, shutter, and aperture until the arrow points to the "0" ... indicating a correct exposure for the amount of light the camera metered.

OR

In any of the semi-auto-modes you select either the aperture (possibly used to control the depth of field of the shot) or shutter (to control the motion of the shot) priority and dial in what you need... then the camera meters the scene and automatically sets the complementary parts of the exposure to provide a correct exposure for the amount of light the camera metered.

Now think about this... in BOTH scenarios... the final exposure was based on producing a correct exposure for the amount of light the camera metered.  Neither is "more accurate" then the other.

This is why I say the ONLY time it would actually be MORE accurate is if you use an incident meter, because an incident meter is checking for the amount of light falling on the subject you care about and NOT using the amount of light being reflected off the subject you care about.  Incident meters are thus more accurate -- but they are more cumbersome and if the shot you're taking is a "landscape", you may not want to hike out 10 miles to "meter" that mount and then hike back to your tripod to dial in the exposure -- so a reflected meter reading is a huge time saver (chimp the histogram if you're worried.)

Go ahead and use ALL the modes on your camera.  There is a reason they are there.  Use the mode most effective for the shot at hand.  Don't fall in the trap of believing that Manual is somehow "better" than the other modes... manual is not necessarily better or worse... it just offers you absolute control.  But if your plan was to just go with whatever it takes to get the meter to zero out in the middle then you're not gaining anything by shooting in manual... you're just taking more time to dial in the exposure then the computer would have used.


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## ShootRaw (Feb 6, 2014)

You do not need a Handheld light meter to be accurate in M mode..Give me a break. In today's cameras.......Matrix metering is quite accurate..Pro's shoot in manual for a reason..Have you seen Jerry ghionis's work? He is one of many who shoot's in Manual on the big wedding day.No handheld meter is needed..It is not about zeroing out to the center for accurate exposure. that is just the starting point to you decide how many clicks to the left or right you need to go to get correct exposure..


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## manaheim (Feb 6, 2014)

bribrius said:


> manaheim said:
> 
> 
> > My suggestion to you... as a newbie... is to put your camera in aperture mode, possibly program mode (not Auto), and just worry about your compositions.
> ...



So put it in P and let the camera do the work for now.  P sets your aperture and your shutter automatically. The only thing it will not adjust is your ISO (which is FINE... for reasons not worth getting into quite yet.)


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## Derrel (Feb 6, 2014)

Exposing to the right used to bring with it a very significant benefit with digital sensors that were made 10,12,13 years ago. If you're using a state of the art digital SLR with one of the new wide-dynamic range and rich-color, low-noise sensors, like say the new SONY-made sensors, oh in like, just for ONE single example, the Nikon D800, FAILING TO expose fully to the right has become in a practical sense, MUCH LESS of a deal-breaker than it used to be back when sensors were very much "sucky", as in the D100 days, or whatnot. Software has also become much,much better, within just the last few years, and it is much easier to get both shadow separation, and highlight control and placement, with a wide variety of exposure variations.

If you look around, you'll see that expose to the right articles on the web are often 10 years old....that was a different time. Please take very,very careful note of what I have written here. I'm not saying that ETTR offers *no benefits*, so please, save your keystrokes and skip the indignant and hoity-toity post-in-response (you know who you are). ETTR was once a cornerstone of good digital best practices...back when both sensors and software were in their infancy. That was a looooong time ago, speaking in sensor and software terms.


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## bribrius (Feb 6, 2014)

TCampbell said:


> Manual is only more accurate if you use an incident light meter to take your meter reading and dial in the exposure based on that and not based on the in-camera meter -- and especially if you're taking multiple meter readings (highlight readings, shadow readings) and then using an exposure which does not clip or blow the range of the camera. You could put your camera into spot metering mode then look for the brightest point and darkest point you can find in the scene, meter those separately, then find the middle exposure -- although matrix or evaluative metering mode will try to do this for you anyway.
> 
> Otherwise consider this:
> 
> ...



okay. I have a question. so I spot meter using the camera, then I do the same exact frame in auto. there is a bright tv on on the right side of the frame (doing this in my living room) cars driving by with a little window glare or shine. I spot meter zero in a neutral object. click. set manual exposure. in the other pic, I let it run in auto. 
The auto setting would take the effects of the tv. cars going by, whatever else wouldn't it? But the manual exposure, ignoring the tv as it was set on a another object more neutral in the setting, ignoring the headlights of vehicles driving by. would give me the more accurate exposure wouldn't it? This is my understanding of metering in manual mode.

Auto mode, take a shot in a dim setting, comes up with "raise flash". Assuming you don't want a flash effect. you cant use auto. Put in aperature priority. camera adjusts aperature. But jacks the iso a liitle. now you have noise. change your noise limitations instead of letting it free float. Does the camera readjusts for you not allowing the iso to free float in ap priority? Don't you have to go in and turn on noise reduction now? Dim room, ap mode. Consider turning on d lighting?
This is where I get confused. which is probably why I don't deal with it. Same room. I would do a quick manual meter off the camera. put my iso at 200. lower my ap down to 2.8 and take a shot. looks over exposed drop the exposure compensation a notch. and bring up the shutter speed. under exposed bring the ap up to 3. something click up the exposure compensation and maybe slow the shutter . 
Is there really a big difference there?
The main difference, I see when comparing what I took in manual and what was done in a auto mode is iso. in manual I tend to be able to keep the iso lower. same frame, I keep a two hundred iso a mode will take the picture at 400. I take it at 400 it takes it at 800. Camera take it at 1600 I took it with a 800 iso. And ap. Camera auto takes it at 4 I took it at three. so Basically a wider aperature with lower iso. Is what seems consistently different.


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## Eagle74 (Feb 6, 2014)

manaheim said:


> My suggestion to you... as a newbie... is to put your camera in aperture mode, possibly program mode (not Auto), and just worry about your compositions.
> 
> Shoot in manual when you realize that shooting in an automatic mode failed you.
> 
> Photography, and the artistry of photography, are INSANELY steep learning curves as it is.  The last thing you need to do is overcomplicate them by throwing away perfectly useful tools that are available on your camera on day one.




Good point, Its alot of fun twirling the dials and adjusting this or that, that by the time I'm done adjusting everything the actual composition of the scene has taken second place. 

I am still at the stage of learning how my camera reacts to different settings, its tempting to waste a scene taking test shots. I think I will leave the testing and all that to when I'm at home puttering about.  In time I'm pretty sure I will be able able to make the most from a technical perspetive of the features of my D7000, but If I don't bring my heart, eyes, creativity to a scene then I defeated the very purpose I bought this thing in the first place. Thanks for the reminder.


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## runnah (Feb 6, 2014)

With raw files and sensors these days as long as you are within 2 stops either way of ideal exposure you are golden.


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## apaflo (Feb 6, 2014)

runnah said:


> With raw files and sensors these days as long as you are within 2 stops either way of ideal exposure you are golden.



True, but only if you shoot at low ISO's or are not at all critical!

Modern cameras with something at or close to 12 stops of dynamic range can shoot at base ISO and there really isn't much difference within a couple stops down from clipping.  A JPEG can only encode about 8 or 9 stops of dynamic range, and a print has even less.  

 But a digital camera loses about 1 stop of dynamic range with each 1 stop increase in ISO sensitivity.  If ISO 200 provides a 3 stop cushion, then at 1600 there is none!  Hence at anything other than base ISO, it still makes a difference.

For example the Nikon D4 is probably the best low light camera currently available, and at ISO 1600 it has less dynamic range (7.88 stops) than a JPEG image can show.  Basically from about ISO 800 on up exposure has to be *exact* because there is no leeway at all, and whatever noise there is in the shadows will either show or shadow detail will be lost.


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## Gavjenks (Feb 6, 2014)

Derrel said:


> Exposing to the right used to bring with it a very significant benefit with digital sensors that were made 10,12,13 years ago. If you're using a state of the art digital SLR with one of the new wide-dynamic range and rich-color, low-noise sensors, like say the new SONY-made sensors, oh in like, just for ONE single example, the Nikon D800, FAILING TO expose fully to the right has become in a practical sense, MUCH LESS of a deal-breaker than it used to be back when sensors were very much "sucky", as in the D100 days, or whatnot. Software has also become much,much better, within just the last few years, and it is much easier to get both shadow separation, and highlight control and placement, with a wide variety of exposure variations.
> 
> If you look around, you'll see that expose to the right articles on the web are often 10 years old....that was a different time. Please take very,very careful note of what I have written here. I'm not saying that ETTR offers *no benefits*, so please, save your keystrokes and skip the indignant and hoity-toity post-in-response (you know who you are). ETTR was once a cornerstone of good digital best practices...back when both sensors and software were in their infancy. That was a looooong time ago, speaking in sensor and software terms.




Better sensors simply give you more dynamic range and also I suppose higher bit depths to divide it up.  Neither can just magically pull data out of an image that is clipped (blown highlights look worse than blocked shadows, completely aside from anything regarding sensor data density, which I've never heard of having been changed much incidentally. I was under the impression that it was a fundamental feature of CCD technology, do you have a citation to suggest that it has changed?).

Yes, more dynamic range means that in a wider range of situations, the image WON'T clip in the first place, simply because there aren't always lights bright enough and local enough to get that much higher than the metered exposure. But it's still fairly common if you're just not paying attention at all. Especially in, like, sunsets, street lamp scenes, windows on a sunny day while shooting indoors, etc.

But you still need to consider whether or not to expose to the right. Ignoring it completely is the equivalent of saying "Oh well modern cards have better crumple zones and better braking tires that make rapid deceleration 50% less likely. So I'm just never going to wear a seatbelt anymore."  Well that's a fine choice... 50% of the time.

Until dynamic range gets so high that no common earthly scene can extend beyond it, ETTR is relevant... even if the linear vs. logarithmic thing isn't an issue (which again, what makes you say it isn't?)


*Edit*: I interpret ETTR as both pushing the histo further right if empty space is to the right OR pulling it more left if there are blown highlights at all. I.e. perfect right snuggly fit, either way. This might not be how others are using the term?


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## Derrel (Feb 6, 2014)

Gavjenks said:


> Derrel said:
> 
> 
> > Exposing to the right used to bring with it a very significant benefit with digital sensors that were made 10,12,13 years ago. If you're using a state of the art digital SLR with one of the new wide-dynamic range and rich-color, low-noise sensors, like say the new SONY-made sensors, oh in like, just for ONE single example, the Nikon D800, FAILING TO expose fully to the right has become in a practical sense, MUCH LESS of a deal-breaker than it used to be back when sensors were very much "sucky", as in the D100 days, or whatnot. Software has also become much,much better, within just the last few years, and it is much easier to get both shadow separation, and highlight control and placement, with a wide variety of exposure variations.
> ...



ETTR was HUGELY important, perhaps critical even, when we had chit sensors, like those in the Nikon D1 back in 2000. ETTR is only *situationally* *critical* now that we have sensors like the new SONY sensors that have 14 EV dynamic range at base ISO. But as a Canon shooter, you're still lagging two EV values behind, so I can appreciate your position and where you're coming from. In plain English, ETTR USED TO BE of huge benefit in almost any situation. Today....not so much. See, I learned that over 13 years of shooting d-slr cameras from multiple generations. 

Maybe some day you can understand the difference between "then" and "now". At one time, people had to turn a crank at the front of their engines to start their automobiles; later on, the "self-starting engine" was developed. At one time, arm strength was a critical factor in driving an automobile...by the late 1930's, that had changed. See how that works?? What was once "critical, every single time" gave way to "no longer the case."

Yes, ETTR is "relevant". But it is no longer "critical", the way it once was. Sensors are better, and software is far better. Maybe you ought to investigate a SONY-sensored camera sometime soon. See what you're missing as far as "Pliability" of the files.

Take a look. See how far SONY has come. http://www.fredmiranda.com/5DIII-D800/index_controlled-tests.html


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## Gavjenks (Feb 7, 2014)

That article had pretty much nothing to do with exposing to the right or any of the reasons you would do so.  I'll be clearer in this post.  There's two things I mean when I personally say ETTR:

1) Lowering the exposure if any highlights are clipped. This happens slightly less often with modern cameras compared to 10 year old ones, but still quite commonly. Only a a few stops of dynamic range have been added in that time, and real world scenes can still have MANY more stops of dynamic range than our modern cameras do sometimes. In such cases, the cameras will (usually, depending where you point it) try and center the exposure, blocking shadows and clipping highlights. I think it generally looks a lot better to shift it so that the highlights are barely not clipped, at the expense of shadows which don't look as bad.  This is still very relevant, perhaps even "critical" in very high DR scenes.

2) Raising the exposure if you aren't using the top part of the histogram (and then lowering it back again in the RAW converter). This is due to the physics of how sensors work and the difference between linear and logarithmic measures. The highest stop in your range has 1/2 of all the data. The second stop has 1/4, etc. (one extra stop = 2x as many photons = half of all the precision up to that point). So if you aren't using the top of your range, you're wasting the most sensitive and precise part of your measuring device.

As far as I am aware, none of this logic of #2 has changed one iota in the last 10 years. The newest of new modern sensors still have half their data in the top 1 stop of their range, unless you have citations to the contrary (I'm not even sure if it's physically possible to have that ever not be true, but maybe).  Thus, this is still exactly as relevant as it ever was. You could argue that with higher bit depths, it doesn't practically MATTER if you waste (overabundant) data.  And sure, okay, but why are we buying new cameras if we are just throwing out their new advantages?

Note that ETTR requires more light, and in low light handheld situations, it may not be worth it, by increasing shake blur. But pretty much any other time that you have the time to do it and are trying to take a top notch photo, you generally should at least consider it, I think. As much now as before.


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## Gavjenks (Feb 7, 2014)

Here's a little graphic I drew up.  This is a toy example of a hypothetical camera that has 4 stops of dynamic range and 5 bit depth, using individual photons as exposure for simplicity.
The X axis represents the range of the camera, similar (not identical) to the X axis in the histogram you see on the back of your LCD. It is scaled by stops.
5 bits = 32 discrete luminosity values possible (let's say 0 = "no photons during exposure, blocked shadow". 31 = "more than we can detect, blown highlight"). They are NOT divided equally across the range. 
The top stop of dynamic range has 1/2 of all the lightness values the sensor can detect, but is only 1/4 of the range, since stops are logarithmic.

Above are two examples of histograms. Normally the LCD screen doesnt have the resolution to show you these differences, but our low bit depth example makes it apparent. One is not exposed to the right. Notice that it has less information and is blockier, because most of the image is falling in the low-precision part of the range. Whereas the one exposed to the right has much more data in it, because it's using the higher precision part of the range. You then edit it in RAW with all this extra data to your liking, then digitally stop back to a proper exposure.

TL;DR: You'll get more posterization if you expose the same image to the left of the histogram than to the right
AFAIK, this is all still as true of modern sensors as older ones.



And when you stop and think about it, it becomes extremely intuitive and necessarily obvious: when you ETTR, you're getting the same image, without clipping any of it, but you're doing so with more light in every part of the image. *Of course* more light = more fine grained information available. You're literally letting more data into the lens, and sensors are fundamentally capable of taking advantage of that extra data (as long as you shoot in RAW, although even a trivial little bit if you don't at the very lowest stops!)

It's like trying to understand somebody on a low bandwidth audio connection versus a higher one.  Same person talking, same sentences, but lower number of data bins makes it almost incomprehensible if you're being stingy with your megabytes.  Same thing here, but you're being stingy with your shutter speed (or whatever).  If you NEED to (very low light), then go for it. Otherwise ETTR.


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## weepete (Feb 7, 2014)

A lot of the time now I use the zone system. So basically I just spot meter on the brightest part of the scene and judge where I want that to be in my exposure (usually it's 1-2 stops overexposed). I'll also check the shadows for clipping and the main subject to see if it falls where I expect it to be but I don't tend to worry too much about that now. If I'm clipped on the shadows or my main subject is going to be well underexposed it's a candidate for HDR and I'l then fit the exposure in to that.

Needless to say in dynamic situations this is not too useful, it only really works if you have time or the lighting is not changing often but seeing as a lot of my shots are landscapes it's proving quite effective so far for me


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## Rick58 (Feb 7, 2014)

The basics are really very simple. There's only one RIGHT exposure. Ask yourself what is most important in your scene. Stopping or enhancing speed? DOF? or unusually bright or dark lighting. Use that for your priority and let the camera do the rest. I usually shoot in manual, but that's only because that's how I learned and I'm too thick to change.


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## EIngerson (Feb 7, 2014)

apaflo said:


> Eagle74 said:
> 
> 
> > Hi everyone,
> ...



I'm curious how auto ISO and exposure compensation fine tunes for you. I'm not knocking your method, I legitimately want to here about it. My way of thinking is, if you mess with exposure comp, you just make your camera choose a different ISO. I NEVER shoot in auto ISO. It's just not a variable I want my camera to choose for me.

Essentially, you've created an "ISO priority" auto mode.


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## kathyt (Feb 7, 2014)

I push to the right when I spot meter off of skin. My tones tend to be right on target, and not underexposed. It just depends on what I am shooting.
*I should also note that I will overexpose about 1/3 of a stop as well.


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## manaheim (Feb 7, 2014)

EIngerson said:


> apaflo said:
> 
> 
> > Eagle74 said:
> ...



Yes. Those were my thoughts exactly.

And while I use automated features on my camera, Auto ISO is almost never one of them.  I have used it exactly twice.


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## apaflo (Feb 7, 2014)

EIngerson said:


> apaflo said:
> 
> 
> > So what's that all mean???  I set Aperture and Shutter Speed for artistic effects.  I let the camera adjust ISO to get an appropriate image, though I might "recalibrate" the light meter a little up or down using Exposure Compensation.  This absolutely invovles monitoring the camera's Blinking Highlight display and the RGB histograms.  Maybe not for every shot, but absolutely for the first few shots until I've got it "right", and every now and then or anytime the light changes to make sure things stay "right".
> ...



    It is an "ISO Priority" mode!  Aperture and Shutter are set manually (technically that sets "exposure"), and the camera adjusts the brightness of the digital data by adjusting ISO according to the light meter reading.  The light meter reading can be calibrated for this specific scene by changing Exposure Compensation, and yes the precise effect is to change ISO (not exposure, but data brightness).

  Hence I might decide that for some given shot I want the DOF that comes from an f/4 aperture, and I may want the motion blur associated with a 1/125 shutter speed.  That defines exactly how much light falls on the sensor (exposure).  The light meter might see the scene as middle grey and set ISO 400.  Of course the scene might actually be mostly a snow bank, and I'll know it needs more exposure, so I might set Exposure Compensation at +1 EV.

At that point taking a shot will provide an historgram, and checking it may reveal that the snow is brighter than I thought, and there's a lot of room on the right side of the histogram, so I'd want to increase compensation to maybe +1.7 EV.  It also could be the snow is a lot darker than I thought, and maybe +0.3 EV is better.   Any of these changes will adjust the *data brightness* by changing the ISO.  The *exposure* (light falling on the sensor) stays exactly the same.

 That is a simplified description, and there are many little details about usage.  Setting up AutoISO and then monitoring the range boundaries, and for that matter the effects of ISO changes, is no more or less complex than what has to be done with Aperture Priority or Shutter Priority.  With any of these modes the camera sets one of the three and the other two are manually set.  Choosing the mode to use is a matter of deciding which artistic effects are most important and which are least.  

Let the camera adjust the least important to provide operational speed, while the photographer sets parameters that affect the most important.   The point of using an Auto mode vs a fully Manual mode is operational speed.  If the scene or the light changes rapoidly, an Auto mode us useful.  For more static subjects, for example studio work or typical landscapes, Auto modes have little if any value.  

*Choose the method that provides the best photography, not the one that sounds the most elitist when discussed on the Internet.*


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## Gavjenks (Feb 7, 2014)

> It is an "ISO Priority" mode!



"___ Priority mode" is a term used to refer to a mode where ____ is not automatically changed by the camera, but instead only by the photographer.
So auto ISO is the opposite of ISO priority mode.  
An ISO priority mode would be one where your main wheel changes ISO directly, and the camera automatically chooses aperture and shutter speed.  Which would be weird.


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## apaflo (Feb 7, 2014)

Gavjenks said:


> > It is an "ISO Priority" mode!
> 
> 
> 
> ...



 Semantics.  Both EIngerson and I put it in quotes for a reason.  His point was precisely well taken, and I expounded on his questions without wasting time on his semantics.  You probably should have followed suit, because given the quoted phrase, he was right and your point is meaningless.


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## Gavjenks (Feb 7, 2014)

There's no need to be all defensive. I was simply pointing out a semantic (as you say) mistake for clarity of anybody following along who doesn't know what priority modes are. It's a beginner's forum. Beginners need consistent semantics. 

Priority means "this is important, so the *photographer *has control of it as a priority."
Aperture priority = you control the aperture and let other things vary.
Shutter priority = you control the shutter speed and let other things vary
etc.

Saying the opposite is potentially confusing to any beginners who are passively learning how their camera modes work as they read any of these threads.


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## unpopular (Feb 7, 2014)

I agree with others, in order to understand ETTR you have to understand reflective metering, understand that zero does not mean 'correct', and a good understanding of the zone system, preferably both the pre- and post-exposure ends of it, at least in theory if not in practice.

a lot of times people will just expose some arbitrary amount over what they arbitrarily decide is 'accurate', and then correct the exposure in post in some arbitrary way. I've even seen this in otherwise respectable books and columns. IMO ETTR is about good old fashion exposure analysis, using data provided by the meter to capture the widest possible range of tones and then processing the gamma according to intent.

So yeah, you kind of have to know the meter pretty well. When I'm not mobile, I'll provide a link to a thread on spit metering.


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## unpopular (Feb 7, 2014)

Oh, and what I am not sure had been mentioned yet, you don't need to be in manual mode to shoot ETTR, it's just a preference by some who do.

and furthermore unless you're into the generic look of evaluative exposure (which in some cases is the best option) I don't really think any AE mode, be it program, aperture or time priority would save you from learning about metering anyway. This whole argument is kind of ridiculous.


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## sk66 (Feb 7, 2014)

ETTR... I don't. Most of the time I don't have the chance to check the histogram and adjust/try again; and I would much rather protect highlights than clip them.

Manual Mode... IMO, you have to understand and be able to use it in order to "purposefully" use the other modes and remain in control. But it's not "better."

Auto ISO... ISO is often the FIRST thing I'm willing to give on. The minor losses in DR/Color depth/etc for a few stops from base are usually much less significant to an image than aperture/SS. If I'm shooting a landscape using a tripod etc, then maybe I can afford to trade in favor of ISO.

My normal mode of operation is A(Av) with spot/cw metering, and auto ISO (limits set). If I also care about SS as much as aperture I'll switch to manual mode. If I have the luxury of caring about ISO as well, I'll turn auto ISO off. If I shot Canon my methodology would be somewhat different as they don't "prioritize"/function in the same manner.


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## EIngerson (Feb 7, 2014)

apaflo said:


> EIngerson said:
> 
> 
> > apaflo said:
> ...




I'm going to play around with this and see how it goes. Thanks for taking the time to respond.


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## table1349 (Feb 7, 2014)

Eagle74,  One thing that I can't stress enough to young photographers is the need to learn and understand light itself.  Once you have a good working knowledge of light, your equipment and how it works then your job becomes much easier.  The histogram is a tool, a useful tool, but  still a tool.  If  you don't understand the basics of that tool, then it's use is diminished.  If you learn and understand light you will gain the ability to know and understand the range a histogram should fall in for a properly exposed photo.  Realize, that properly exposed doesn't mean just what the meter says, but what you as the photographer are trying to achieve. 

This may give you a bit of a start on the understanding of light.  Understanding Light in Photography ? Beginner Level | Beyond Megapixels


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## Eagle74 (Feb 7, 2014)

gryphonslair99 said:


> Eagle74,  One thing that I can't stress enough to young photographers is the need to learn and understand light itself.  Once you have a good working knowledge of light, your equipment and how it works then your job becomes much easier.  The histogram is a tool, a useful tool, but  still a tool.  If  you don't understand the basics of that tool, then it's use is diminished.  If you learn and understand light you will gain the ability to know and understand the range a histogram should fall in for a properly exposed photo.  Realize, that properly exposed doesn't mean just what the meter says, but what you as the photographer are trying to achieve.
> 
> This may give you a bit of a start on the understanding of light.  Understanding Light in Photography ? Beginner Level | Beyond Megapixels




Thanks for the link, just read it and bookmarked the site for later. 

Just got my copy of Understanding Exposure today as well.  I was getting overwhelmed with how many different things there is to learn. I am loving photography and its becoming apparent there is no end to learning and growing.  Y'all who know so much thank you for contributing.


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## apaflo (Feb 7, 2014)

Gavjenks said:


> I was simply pointing out a semantic (as you say) mistake [...]



You were and are still just confusing things.  There was no semantic mistake.  We put the words in quotes to show that the usage was not normal.


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## EIngerson (Feb 8, 2014)

Gavjenks said:


> There's no need to be all defensive. I was simply pointing out a semantic (as you say) mistake for clarity of anybody following along who doesn't know what priority modes are. It's a beginner's forum. Beginners need consistent semantics.
> 
> Priority means "this is important, so the *photographer *has control of it as a priority."
> Aperture priority = you control the aperture and let other things vary.
> ...




It's okay to be wrong bro.


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## unpopular (Feb 8, 2014)

sk66 said:


> ETTR... I don't. Most of the time I don't have the chance to check the histogram and adjust/try again; and I would much rather protect highlights than clip them.



If you use the spot meter properly and have a good understanding of camera latitude then you will never, ever clip with ETTR. In fact, this is the main reason I use the technique. Clipping is only a risk if you arbitrarily increase exposure without paying attention to hilight placement.


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## WayneF (Feb 8, 2014)

Gavjenks said:


> There's no need to be all defensive. I was simply pointing out a semantic (as you say) mistake for clarity of anybody following along who doesn't know what priority modes are. It's a beginner's forum. Beginners need consistent semantics.
> 
> Priority means "this is important, so the *photographer *has control of it as a priority."
> Aperture priority = you control the aperture and let other things vary.
> ...





Don't worry about them, you are of course precisely correct.   I think "ISO Priority" is a Pentax term, where user selects ISO.  It does not mean Auto ISO, instead, it rules it out.

In a similar way, Nikon and Canon say Aperture Priority and Shutter Priority meaning exactly what you said (user sets it, to be given priority).  This is true regardless if we selected ISO, or let Auto ISO do it.


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## unpopular (Feb 8, 2014)

anyway - OP here is the link I promised:

http://www.thephotoforum.com/forum/...262171-spot-metering-how-use.html#post2389739

The most important point is that "zero" does not mean "correct"


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## WayneF (Feb 8, 2014)

unpopular said:


> anyway - OP here is the link I promised:
> 
> http://www.thephotoforum.com/forum/...262171-spot-metering-how-use.html#post2389739
> 
> The most important point is that "zero" does not mean "correct"



Right.  Spot metering is an advanced technique,  it is Anything But beginners point&shoot.   Reflected meters can only strive for a middle gray result, because it is all the smart they have.  Many typical scenes do have wide range and do average about middle gray, which is the only basis of the system.  But if we are going to pick our own spot to meter, that spot better be near middle gray.  It does not come out "accurate".  It comes out middle gray (equivalent).   A face probably should not be middle gray.  It can still work if we know to compensate it about +1EV.  But Spot metering is anything but a general concept.


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## unpopular (Feb 8, 2014)

Well, yes. It will only be accurate if the exposure is "uncompensated", or exposed at ±0ev, that is "zeroed". There are a lot of decent references in nature for middle grey, green foliage, 45° from the horizon opposite the sun (at which point you may as well use Sunny 16). There are other reference concrete is typically +1ev, asphalt typically -2ev.

But really, I don't think looking at exposure this way is particularly useful. I think it's better to considering how the image is to be rendered, and this should be talked about early on if you're serious about photography. Maybe for the beginner this concept won't be fully developed, but it's important that exposure isn't seen as something that has only one correct answer for.

I really don't like the idea of a "proper exposure".


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## apaflo (Feb 8, 2014)

unpopular said:


> Well, yes. It will only be accurate if the exposure is "uncompensated", or exposed at ±0ev, that is "zeroed". There are a lot of decent references in nature for middle grey, green foliage, 45° from the horizon opposite the sun (at which point you may as well use Sunny 16). There are other reference concrete is typically +1ev, asphalt typically -2ev.
> 
> But really, I don't think looking at exposure this way is particularly useful. I think it's better to considering how the image is to be rendered, and this should be talked about early on if you're serious about photography. Maybe for the beginner this concept won't be fully developed, but it's important that exposure isn't seen as something that has only one correct answer for.
> 
> I really don't like the idea of a "proper exposure".



Proper exposure is correct exposure, and that is an exposure that produces the image exactly as the photographer wants it!

Statements like "underexpose by 1 stop to get what you want" are contradictory.  What it really means is that the light meter reading will over expose by 1 stop.


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## vintagesnaps (Feb 8, 2014)

Why would zeroing out the meter give unexpected exposures? I've always used the meter to let me know if I'm getting a proper exposure, which to me means that I'm getting the proper amount of light coming in to the camera. How I get there is where shooting manual comes into it - I can adjust the aperture, or if I want to maintain a certain depth of field I can adjust the shutter speed, or vice versa, or some of both. 

There might be situations where you'd want to adjust from what the meter is indicating, if the meter is fluctuating when the light is changeable (sun in and out) etc. When I'm shooting B&W film sometimes I bracket shots to make sure I have a negative that isn't too thin or too dense, but I have yet to figure out why people or websites say to always under or over expose. 

When I'm shooting digitally (I'm a film photographer too) I usually shoot Raw and all manual and I don't get blinkys etc. so I go by what the meter indicates as to whether or not I'm getting the exposure I need, then adjust from there.


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## sk66 (Feb 8, 2014)

unpopular said:


> sk66 said:
> 
> 
> > ETTR... I don't. Most of the time I don't have the chance to check the histogram and adjust/try again; and I would much rather protect highlights than clip them.
> ...



Did you note that I said I generally don't have time to check the exposure/adjust right/try again?
And the ETTR technique also depends A LOT on the accuracy of your camera's histogram/blinkies... some lie quite badly (my D800 does).


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## WayneF (Feb 8, 2014)

sk66 said:


> Did you note that I said I generally don't have time to check the exposure/adjust right/try again?
> And the ETTR technique also depends A LOT on the accuracy of your camera's histogram/blinkies... some lie quite badly (my D800 does).



Blinkies:  You are not watching the proper RGB histogram. Sounds like you may not understand about luminosity histograms.  You need to read Two types of Histograms  (it is short and very easy).

And those who imagine that reflective meters always indicate the correct exposure are called beginners.


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## Eagle74 (Feb 8, 2014)

vintagesnaps said:


> Why would zeroing out the meter give unexpected exposures? I've always used the meter to let me know if I'm getting a proper exposure, which to me means that I'm getting the proper amount of light coming in to the camera. How I get there is where shooting manual comes into it - I can adjust the aperture, or if I want to maintain a certain depth of field I can adjust the shutter speed, or vice versa, or some of both.
> 
> There might be situations where you'd want to adjust from what the meter is indicating, if the meter is fluctuating when the light is changeable (sun in and out) etc. When I'm shooting B&W film sometimes I bracket shots to make sure I have a negative that isn't too thin or too dense, but I have yet to figure out why people or websites say to always under or over expose.
> 
> When I'm shooting digitally (I'm a film photographer too) I usually shoot Raw and all manual and I don't get blinkys etc. so I go by what the meter indicates as to whether or not I'm getting the exposure I need, then adjust from there.



I'm just saying shooting in Manual in particular and zero'ing out the meter don't always give me what I am looking for. Example: shooting indoors using flash something white or reflective in close proximity to the flash get clipped. Another would be blowing out the light coming through a window because i use the subject focus point to meter off of. I know this isn't specific to manual mode. This is just my something I have to learn, keep in mind I'm pretty much a beginner, but I do like learning about this.

The main point of my question was if Exposing to the Right provided any kind of practical benefit if there is latitude in the histogram to move it right.


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## sk66 (Feb 8, 2014)

WayneF said:


> sk66 said:
> 
> 
> > Did you note that I said I generally don't have time to check the exposure/adjust right/try again?
> ...



Believe me, I understand histograms and blinkies. If you think the histograms (RGB or Luminance) or blinkies shown in the camera are accurate you would be mistaken. Quite possibly significantly. Even using a Uni-WB will only get you close... and I found it not worth the hassles.


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## WayneF (Feb 8, 2014)

sk66 said:


> WayneF said:
> 
> 
> > sk66 said:
> ...



I am still wondering if you do understand luminosity histograms.   

The camera offers two histograms,  the single one containing luminosity, which is a math abstraction of gray scale, which it isn't, which DOES NOT EVEN SHOW YOUR ACTUAL DATA ( but it is default unless you look further).

And the one showing the three Red, Green, Blue graphs, which is your real data. 

 The RGB histogram is NOT wrong  (255 is NOT ambiguous).  But yes, it is showing JPG with camera WB, when you may be using Raw with your own WB.

 The single Luminosity graph is not even close to anything.

Try the link provided, it will make a huge difference for you.  It is something we all have to know to get any use out of the histogram.


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## Ysarex (Feb 8, 2014)

WayneF said:


> And the one showing the three Red, Green, Blue graphs, which is your real data.
> 
> The RGB histogram is NOT wrong  (255 is NOT ambiguous).  But yes, it is showing JPG with camera WB, when you may be using Raw with your own WB.



The Red Green Blue graphs are my real data, but it's showing JPEG? I thought the raw capture was my real data. So you're saying the RGB histogram is NOT wrong just that it's not my raw data which therefore must not be real data so the JPEG must be my real data. But if my raw data is my real data and the RGB histogram is showing JPEG then it must be wrong for my real data. Sounding very confused here.

Joe


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## apaflo (Feb 8, 2014)

sk66 said:


> If you think the histograms (RGB or Luminance) or blinkies shown in the camera are accurate you would be mistaken. Quite possibly significantly. Even using a Uni-WB will only get you close... and I found it not worth the hassles.



In fact the histograms are *precisely* accurate!  They just *aren't* necessarily displaying what photographers want displayed.  They are accurately showing exactly what is in the camera generated JPEG image, not what is in the RAW sensor data; nor is it what will be in a RGB image (JPEG, TIFF or whatever) generated with an  external computer program.  In particular White Balance, Brightness, and Contrast parameters will all drastically change how an histogram looks.

 If you want to see an histogram that accurately displays what is in the RAW sensor data, in particular to use for ETTR or even just generally setting exposure, it is a fact that UniWB can be made as accurate 1/10th of an fstop.  And yes that can be a hassle, given that you give up being able to use the in camera JPEG as a preview (don't use that JPEG to show Granny what she looks like, or you'll get tossed out the door!)

 Commonly what is worth doing in many cases but not all, is adjusting the camera JPEG generator for low relatively contrast, and the using the brightness level to cause the histogram to be very close in terms of the exposure.  It will usually be within 1/4 of a stop, and virtually always within 1/2 a stop.  Hence adjusting it to be about 1/3 a stop high in brightness will provide a RAW file that never clips highlights and is always easily processed to provide nearly the maximum dynamic range the camera is capable of.


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## WayneF (Feb 8, 2014)

Ysarex said:


> The Red Green Blue graphs are my real data, but it's showing JPEG? I thought the raw capture was my real data. So you're saying the RGB histogram is NOT wrong just that it's not my raw data which therefore must not be real data so the JPEG must be my real data. But if my raw data is my real data and the RGB histogram is showing JPEG then it must be wrong for my real data. Sounding very confused here.
> 
> Joe





If you shoot Raw, you get Raw, and the only problem is, the rear LCD shows RGB, and cannot show Raw.  Nor can our computer monitors show Raw. Our tools show RGB.

So Raw files include a small embedded JPG with the camera properties in it (WB, contrast, etc), to be shown on the rear LCD.   And since Raw files are not RGB, my notion is the RGB histogram obviously comes from that JPG too.

Raw does not have gamma either, but gamma only changes the data between 0 and 255, and a quirk of exponents (anything to the power of 0 or 1 is 0 or 1) is that gamma  cannot change 0 or 255 endpoints ( so no concern about gamma, it cannot induce clipping).

But WB can shift the dickens out of it, esp red and blue channels in opposite directions, and so WB can shift data to cause clipping.  Raw could not care less about WB yet, but unless your JPG is ballpark WB, the histogram could be a bit different than what the final RGB produce later from Raw.  Histogram shows that shifted JPG histogram.

Auto WB is fairly poor, but I use it with Raw, as a quicky way to see ballpark color on the rear LCD, to be unconcerned about clipping.  It is halfway close, unimportant if it is exactly right or not.


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## apaflo (Feb 8, 2014)

WayneF said:


> So Raw files include a small embedded JPG with the camera properties in it (WB, contrast, etc), to be shown on the rear LCD.   And since Raw files are not RGB, my notion is the RGB histogram obviously comes from that JPG too.



 The camera actually embeds a full sized JPEG in the RAW file, as well as a small version for preview on the LCD.  If the mode is set to RAW only, the JPEG file is discarded, while if set to JPEG mode only it is the RAW file that is discarded.  

 The camera's histogram is from a full sized JPEG, generated using whatever parameters the camera has configured.

 If the camera's mode produces a JPEG file, that histogram precisely represents that JPEG file.  Likewise if a RAW file is produced by the camera and  another JPEG is produced using an external RAW converter that can use the in camera configuration as a default (which perhaps is true only of the manufacturer's conversion software) then the in camera histogram will also accurately represent what is in that JPEG image.

 Any JPEG, TIFF or RGB format image file produced from the original RAW file in any other way will not match the camera's histogram.


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## WayneF (Feb 8, 2014)

apaflo said:


> The camera actually embeds a full sized JPEG in the RAW file, as well as a small version for preview on the LCD.




I cannot see inside the NEF file, but I don't see any evidence of that.   

Here is NEF only, and NEF + Fine.   On fixed tripod, on unchanged subject.








First line is NEF, followed by NEF + Fine.   Second NEF is 106 KB larger (why, I don't know).

If the JPG is 30 MB, and if it is in there, why isn't the second NEF 30 MB larger?


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## Ysarex (Feb 8, 2014)

WayneF said:


> Ysarex said:
> 
> 
> > The Red Green Blue graphs are my real data, but it's showing JPEG? I thought the raw capture was my real data. So you're saying the RGB histogram is NOT wrong just that it's not my raw data which therefore must not be real data so the JPEG must be my real data. But if my raw data is my real data and the RGB histogram is showing JPEG then it must be wrong for my real data. Sounding very confused here.
> ...



So if I think the raw capture is my real data then the RGB histograms displayed on the camera are not showing me my real data. They are graphs of how the camera processing software has turned my real data into a JPEG.

Joe


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## WayneF (Feb 8, 2014)

Ysarex said:


> WayneF said:
> 
> 
> > So if I think the raw capture is my real data then the RGB histograms displayed on the camera are not showing me my real data. They are graphs of how the camera processing software has turned my real data into a JPEG.
> ...


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## Ysarex (Feb 8, 2014)

WayneF said:


> Ysarex said:
> 
> 
> > WayneF said:
> ...


----------



## apaflo (Feb 8, 2014)

WayneF said:


> apaflo said:
> 
> 
> > The camera actually embeds a full sized JPEG in the RAW file, as well as a small version for preview on the LCD.
> ...



Apparently you wanted something to show there, but I don't see whatever it was.

Regardless, NEF files actually have perhaps three different sized JPEG images embedded.  There is a full sized JPEG, there is a smaller JPEG for preview, and there is an even smaller one used when multiuple images are shown on the LCD screen.

EXIFTOOL is a program that can extract the embedded JPEG images.  From the NEF file, using options "-b -JPGfromRAW" extracts a fullsized JPEG, options "-b -OtherImage" extracts a smaller JPEG, and "-b -preview" extracts and even smaller JPEG.   From a Nikon D4 the sizes are 4928x3280 for the fullsized, 1632x1080 for the small, and 570x375 for the even smaller JPEG.  If the camera produces a JPEG file it is possible to extract the same 570x375 preview file from the fullsized JPEG too.  I'm pretty sure there is also a 120x80 image embedded as a comment in one or more of those JPEG images but I can't remember the convoluted method to extract it.

Other brands of camera, and for that matter older models of Nikon cameras, have different embedded JPEG images in the RAW files, but as far as I know virtually all of them do have something there.


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## table1349 (Feb 9, 2014)




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## bribrius (Feb 9, 2014)

vintagesnaps said:


> Why would zeroing out the meter give unexpected exposures? I've always used the meter to let me know if I'm getting a proper exposure, which to me means that I'm getting the proper amount of light coming in to the camera. How I get there is where shooting manual comes into it - I can adjust the aperture, or if I want to maintain a certain depth of field I can adjust the shutter speed, or vice versa, or some of both.
> 
> There might be situations where you'd want to adjust from what the meter is indicating, if the meter is fluctuating when the light is changeable (sun in and out) etc. When I'm shooting B&W film sometimes I bracket shots to make sure I have a negative that isn't too thin or too dense,* but I have yet to figure out why people or websites say to always under or over expose.
> *
> When I'm shooting digitally (I'm a film photographer too) I usually shoot Raw and all manual and I don't get blinkys etc. so I go by what the meter indicates as to whether or not I'm getting the exposure I need, then adjust from there.




That's happened to me and not just here. "its under exposed" someone says. Im thinking yeah, no ****, it was taken at night it is supposed to look dim lighted. I bring up the light. Then someone else says " you blew out the highlights". well yeah, no ****. There is only so much you can jack up the light on something taken at night to make it look like it was taken during the day to appease those who might think it is underexposed.
People throw this stuff around quite a bit. which is why I pay attention on here to learn, but I don't take it all seriously? Because unless they are with you, when you take it, to see it first hand what the scene is. Then they are really guessing about some of this stuff and haven't a clue what they are talking about. NOt to mention I had zero comments on a photo I put on here (must have thought it was bad?) that is now hanging on someones wall. Another I got negative reviews on here, (but watch me sell it). So I listen for what I can learn and ignore a good portion of the rest. Happy to see this thread it turned out well. Im picking up some good info on here just reading along. im going to read it through again when I have more time.


----------



## sk66 (Feb 9, 2014)

apaflo said:


> sk66 said:
> 
> 
> > If you think the histograms (RGB or Luminance) or blinkies shown in the camera are accurate you would be mistaken. Quite possibly significantly. Even using a Uni-WB will only get you close... and I found it not worth the hassles.
> ...



I can agree with all of that... I found when using a Uni-WB I *also* had to adjust the Jpeg settings in order to get it relatively close.
Since ETTR is not of much use to me (mostly wildlife/action in variable lighting) I found it not worth the hassles.


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## WayneF (Feb 9, 2014)

Ysarex said:


> Later in the computer I can see histograms of my raw data before I process it to a final RGB photo as well as histograms of that final RGB photo.



No, Adobe (or whatever Raw editor) is not showing a histogram of the Raw data.  Nothing does.  The Raw editor is not showing Raw data at all.  It is necessarily converting Raw to a RGB image, to be able to compute a RGB histogram, and to be able to show anything on your RGB monitor. You can guide that conversion, as you please.   Camera has the same issue on its RGB rear LCD screen, Raw cannot be shown.

So, I guess you can think of the "real data" as being any point you please, but RGB is all you can see (it is necessarily your own only starting point).  

What is clear is that the single gray histogram in the camera is not conceivably real, and can be extremely misleading.


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## WayneF (Feb 9, 2014)

apaflo said:


> Apparently you wanted something to show there, but I don't see whatever it was.
> 
> Regardless, NEF files actually have perhaps three different sized JPEG images embedded.  There is a full sized JPEG, there is a smaller JPEG for preview, and there is an even smaller one used when multiuple images are shown on the LCD screen.
> 
> ...



I did read your post wrong, I cannot find now what I thought it said (regarding outputing BOTH file types).  I was expecting more size from a sum.  Compression is unknown, but we see Fine JPG is 30MB, and we know uncompressed 12 bit Raw is 1.5x larger than uncompressed 8 bit RGB, and so the 50MB sum seems insufficient for both.

I use ExifTool, it is all I have found that can show most of the newer D800 Exif format.  I had not bothered with the command line functions, but looking today, I see this (-ee) in a Raw file:

Subfile Type                    : Reduced-resolution image     (so 160x120 RGB uncompressed)
Image Width                     : 160
Image Height                    : 120
Bits Per Sample                 : 8 8 8
Compression                     : Uncompressed
Photometric Interpretation      : RGB                


Subfile Type                    : Reduced-resolution image    (Size not specified, but it says reduced resolution)
Compression                     : JPEG (old-style)
X Resolution                    : 300
Y Resolution                    : 300
Resolution Unit                 : inches
Jpg From Raw Start              : 1001984
Jpg From Raw Length             : 3982880
Y Cb Cr Positioning             : Co-sited   


Subfile Type                    : Full-resolution Image    (the Raw data)
Image Width                     : 7424
Image Height                    : 4924
Bits Per Sample                 : 14
Compression                     : Nikon NEF Compressed
Photometric Interpretation      : Color Filter Array
Strip Offsets                   : 4985344
Samples Per Pixel               : 1
Rows Per Strip                  : 4924
Strip Byte Counts               : 41391624
X Resolution                    : 300
Y Resolution                    : 300
Planar Configuration            : Chunky
Resolution Unit                 : inches
CFA Repeat Pattern Dim          : 2 2
CFA Pattern 2                   : 0 1 1 2
Sensing Method                  : One-chip color area


Subfile Type                    : Reduced-resolution image    (same again? no size)
Compression                     : JPEG (old-style)
X Resolution                    : 300
Y Resolution                    : 300
Resolution Unit                 : inches
Other Image Start               : 176640
Other Image Length              : 825308
Y Cb Cr Positioning             : Co-sited

I suppose extracting them would show a size.

I am wondering if "extract a full size JPG" means it creates one for us, or if it was already in there.  I wonder where the bytes come from? I guess I am not yet a believer about a full size JPG.


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## sk66 (Feb 9, 2014)

WayneF said:


> The RGB histogram is NOT wrong  (255 is NOT ambiguous).  But yes, it is showing JPG with camera WB, when you may be using Raw with your own WB.
> 
> The single Luminosity graph is not even close to anything.



Here's a test I did for the D800 using an image designed to push histograms from Cambridge in Color website.

Here's the histograms in camera. Jpeg settings set so that the image looked as accurate as possible to the original.


Here's the same image opened in PS (raw; LR looks very similar). The histograms here look very much as the test image was designed to make them (some minor differences due to not capturing the entire original image)


These are both of the exact same file. Some will note that there is obviously some interpretation being done to the raw file in order to display it... I did everything possible to make it "neutral" (i.e. adobe standard, as shot, etc.). These differences are simply a fact of life and can't be entirely avoided. Even using a Uni-WB I wasn't able to get the Jpeg histograms "accurate," but I could get the luminance "closer." 

The D800 seems particularly bad, my D4 is MUCH closer without any tweaking. This may be due to the "level" the camera is targeted to...I don't know.
I believe a lot of what we call "headroom" in the raw file is due to the manufacturers' intent to protect the harsh clipping characteristic of a digital sensor (i.e. the REI/reported ISO being higher than actual sensitivity); and many cameras do not use 255 as the point for "clipping." (item 9 in the link). They use something more like 245-250.

IMHO, this is not necessarily "bad;" whites above ~245 and blacks below ~10 are not of much good for display/print. The D800 also seems to be applying some "perceptual bias" to the histograms and shifting them based upon their "perceptual weight" (30/59/11% R/G/B). and the luminance histogram is more of a "stack up" of the others instead of a true luminance graph.

What do the manufacturers have to say about this? Here's the disclaimer in the Nikon owner's manual: "camera histograms are intended as a guide only and may differ from those displayed in imaging applications." I.e. differ from "the real ones." Canon doesn't even bother to mention it.


edit to add: it is interesting to note that upon initial opening into PS the histograms will show the camera jpeg "cached" histograms with an alert/update icon. LR does not show the "cached" histograms.


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## chuckdee (Feb 9, 2014)

Understanding the basics of exposures is the first thing you should learn.  Once you learn that, everything will start to make a lot more sense and will make you a better photographer.  Do a search for F16 sunny rule.  Print out a chart and keep it with you when you go and shoot.  When you know what exposures are right for certain conditions, you can then make on the fly adjustments and can pinpoint a certain area of your frame for the correct exposure.


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## Gavjenks (Feb 9, 2014)

WayneF said:


> If you shoot Raw, you get Raw, and the only problem is, the rear LCD shows RGB, and cannot show Raw.  Nor can our computer monitors show Raw. Our tools show RGB.


Many programs on the computer can and do show the RAW histogram (the cameras could too, they just don't).
See for yourself. Set your camera to some really ridiculous settings like +maximum contrast and +maximum saturation (so that the jpeg histo will be noticeably much different than the RAW), then snap a photo in RAW+jpeg mode.

Open the jpeg in photoshop and check out the histo, then open the RAW in different RAW editors and look at the starting histo. In any program I've ever used, they are quite different, suggesting that the RAW converter really is showing the RAW histogram. And there's no good reason why it wouldn't do that, since the histogram is just counting up numbers of dots with each color/lightness, and the pattern of them doesn't matter.

And if you want an accurate histogram in camera, just set all your settings to "neutral" or "zero" or whatever so that it makes minimum adjustments when converting to jpeg and thus minimal differences between the RAW and the LCD histogram. It still won't be absolutely perfect, but almost. The higher bit depth of the RAW doesn't matter for the LCD, because the LCD doesn't have that kind of resolution anyway.


Of course, if you ever shoot jpeg only, then don't set all your settings to zero, because you'll get horrible looking images. it's only if you know you'll be editing from RAW later ("custom shooting modes" are good for this to switch all the settings instantly)


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## apaflo (Feb 9, 2014)

WayneF said:


> I suppose extracting them would show a size.
> 
> I am wondering if "extract a full size JPG" means it creates one for us, or if it was already in there.  I wonder where the bytes come from? I guess I am not yet a believer about a full size JPG.



Exiftool will not create or generate anything.  It extracts data from tags.

But it doesn't take much to realize there necessarily has to be a full sized JPEG available while the RAW file is available on the camera...  to allow the magnified view available on the LCD.


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## AlanKlein (Feb 9, 2014)

I use a thirty-year-old Mamiya RB67 Professional medium format film camera for my landscape photography. All manual. I use a hand held meter, usually in incident mode, to calculate the correct exposure. I then dial in the aperture, shutter and focus adjusting for depth of field. I then release the shutter in mirror up position to reduce vibrations.

And then I bracket two more - one stop above and one stop below. Just to be sure.

Isn't manual terrific?


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## Ysarex (Feb 9, 2014)

WayneF said:


> Ysarex said:
> 
> 
> > Later in the computer I can see histograms of my raw data before I process it to a final RGB photo as well as histograms of that final RGB photo.
> ...



I didn't say Adobe (or whatever Raw editor) was showing me a histogram of the Raw data. You're making false assumptions. I said, "Later in the computer I can see histograms of my raw data before I process it to a final RGB photo..."; see illustration below.

So I guess I do think the sensor raw capture is my "real data" and I do examine it carefully all the time to make sure I'm getting the best possible exposures. It would be nice if I could do that in the field but I'm happy with a process where I review my "real data" later and use that review to inform my work behind the camera. For me it's a more precise method than relying on the Red Green and Blue histograms displayed on the camera which we know have been interpreted by the camera processing software and do not directly represent my "real data."

This thread began with a question about ETTR. To practice ETTR you need a way to examine the raw data as directly as possible to assess how you're exposing the sensor. Looking at data derived from the camera processed JPEG (camera manufacturer histograms of whatever flavor) is indirect and although it may be useful and possible to interpolate from that information it's off mark to suggest that it's anywhere near the "real data."

Joe


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## WayneF (Feb 9, 2014)

Gavjenks said:


> Many programs on the computer can and do show the RAW histogram (the cameras could too, they just don't).



Many?  Not hardly. Name one sold on Amazon that does.  Sure, it is not impossible for someone to write a program to analyze raw files (nerd stuff), but the common stuff sold to users do not bother.  No point.  Editors show expected output after your edits.  The first and most necessary required part of that is RGB conversion.



> See for yourself. Set your camera to some really ridiculous settings like +maximum contrast and +maximum saturation (so that the jpeg histo will be noticeably much different than the RAW), then snap a photo in RAW+jpeg mode.



Yes, certainly much different, but not because it is showing Raw. That is to say, it can only show RGB converted from Raw (the purpose of the raw editor, because that is only thing your monitor can show. Printers cannot show raw either.)    True, the camera settings are not in Raw.   Raw is Raw.  Raw editors do not pick up the camera settings from Exif (excluding Nikon Raw editors, and excluding a fairly poor try at recovering white balance).  The camera settings are not in Raw data, but there is advantage in having the camera show an approximately correct JPG to represent the raw image you hope to achieve.  Auto WB does it for me (not claiming Auto WB is correct, but it is convenient and better then some obviously wrong choice).  It does not matter to the Raw conversion, it will be set then.



> Open the jpeg in photoshop and check out the histo, then open the RAW in different RAW editors and look at the starting histo. In any program I've ever used, they are quite different, suggesting that the RAW converter really is showing the RAW histogram. And there's no good reason why it wouldn't do that, since the histogram is just counting up numbers of dots with each color/lightness, and the pattern of them doesn't matter.



Of course they are different, but it suggests to me that the raw data simply does not have the camera settings in it. The Raw editor is showing RGB created from the Raw data.  This is what Raw editors do, convert to RGB.   Computer monitors cannot show Raw.     Raw data is Bayer, RGGB, one color at each pixel, and RGB is interpolated frfom raw to be three RGB colors at each pixel. 

When and if "both" were edited to be "correct", they would be more similar.


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## apaflo (Feb 9, 2014)

Gavjenks said:


> Many programs on the computer can and do show the RAW histogram (the cameras could too, they just don't).
> See for yourself. Set your camera to some really ridiculous settings like +maximum contrast and +maximum saturation (so that the jpeg histo will be noticeably much different than the RAW), then snap a photo in RAW+jpeg mode.
> 
> Open the jpeg in photoshop and check out the histo, then open the RAW in different RAW editors and look at the starting histo. In any program I've ever used, they are quite different, suggesting that the RAW converter really is showing the RAW histogram. And there's no good reason why it wouldn't do that, since the histogram is just counting up numbers of dots with each color/lightness, and the pattern of them doesn't matter.



     What that suggests is only that most RAW converters are not able to use the camera's configuration for defaults.  The histogram is not of the RAW sensor data at all, it is from the JPEG produced with the program's default configuration, which of course is different than an histogram of the camera produced JPEG.  Without changing the RAW converter configuration, write the RGB image to a JPEG and use that same editor to compare it with the camera produced JPEG.  Different, of course.  And neither is a RAW histogram. 

 There are programs that do show a RAW histogram, and they are definitely labeled as such.   UFRAW is a RAW converter that has both a RAW histogram and one for the current RGB conversion.



> And if you want an accurate histogram in camera, just set all your settings to "neutral" or "zero" or whatever so that it makes minimum adjustments when converting to jpeg and thus minimal differences between the RAW and the LCD histogram. It still won't be absolutely perfect, but almost. The higher bit depth of the RAW doesn't matter for the LCD, because the LCD doesn't have that kind of resolution anyway.



  The result isn't even close to accurate.  It might be "useful" though, but that depends on the skill of the photographer at interpeting the data.  There are very valid arguments for using an accurate White Balance, and there are other valid arguments for using only Daylight White Balance.  In particular gamma (contrast) should be set relatively low.   (Bit depth of the RAW, for an histogram, only affects scaling for the graph's axis and is not related at all to LCD resolution.)



> Of course, if you ever shoot jpeg only, then don't set all your settings to zero, because you'll get horrible looking images. it's only if you know you'll be editing from RAW later ("custom shooting modes" are good for this to switch all the settings instantly)



 ETTR is of no value when shooting JPEG only, and the histogram is exactly what it should be.  It always very accurately shows data for the JPEG.


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## WayneF (Feb 9, 2014)

apaflo said:


> Exiftool will not create or generate anything.  It extracts data from tags.
> 
> But it doesn't take much to realize there necessarily has to be a full  sized JPEG available while the RAW file is available on the camera...   to allow the magnified view available on the LCD.



I agree both notions are possibly true, and would be reasonable.  Or it is also conceivably true  both instances could convert and create what they need for the job at hand.  I  don't know details.  And agreed that it would be a bit heroic for ExifTool.    But if just assuming, it would seem expedient for Nikon, no other processing load at that display zoom time.

I do still wonder how the 30MB of full size JPG can fit into the 50MB NEF file?  


And now I'm wondering how I came up with a 30MB JPG file?     Obviously it is, but the D800 manual says Fine JPG averages 16MB.   I don't shoot much JPG, I would use DX for those uses anyway.  Photoshop Image Size shows this one as size 103 MB, which it obviously should be.  So it would seem my Fine got about 3:1 compression, and the manual assumes about 6:1.   I assumed my image should be a smaller JPG than normal, it is a shot of my computer screen, and half of it is white. However 100% shows the pixel grid, so I guess it has extreme fine detail, a poor choice for this.   

Still, this case is 30MB JPG and a 50MB sum, so I wonder how that can fit in there?  Obviously, it must not be Fine.


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## The_Traveler (Feb 9, 2014)

Somewhere back in the prior 78 posts at least twice it was said that there is only one correct exposure.
There is an assumption enclosed in that statement that is incorrect. 
There is no guarantee that any single exposure that will provide the desired sufficiently good detail in the highlights and the shadows and will expose the centers of interest the way you want.
Mother Nature doesn't care.


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## WayneF (Feb 9, 2014)

Ysarex said:


> I didn't say Adobe (or whatever Raw editor) was showing me a histogram of the Raw data. You're making false assumptions. I said, "Later in the computer I can see histograms of my raw data before I process it to a final RGB photo..."; see illustration below.



Sorry, I just read the words you wrote.  It is already processed, and it is always showing the RGB photo that it will output (usually after you do a few more things).  But it never shows a histogram of raw data (which I think is your own complaint). 



> So I guess I do think the sensor raw capture is my "real data" and I do examine it carefully all the time to make sure I'm getting the best possible exposures. It would be nice if I could do that in the field but I'm happy with a process where I review my "real data" later and use that review to inform my work behind the camera. For me it's a more precise method than relying on the Red Green and Blue histograms displayed on the camera which we know have been interpreted by the camera processing software and do not directly represent my "real data."



Well, the RGB histogram is as good as it gets.  It works out really well in practice.  If unsatisfactory, go with the alternative I guess  (which the only alternative is shooting JPG).



> This thread began with a question about ETTR. To practice ETTR you need a way to examine the raw data as directly as possible to assess how you're exposing the sensor. Looking at data derived from the camera processed JPEG (camera manufacturer histograms of whatever flavor) is indirect and although it may be useful and possible to interpolate from that information it's off mark to suggest that it's anywhere near the "real data."



ETTR seems a mixed bag.  The original idea was with techies, pushing everything as far right as it will go (which is possibly overexposure, but not clipping), so that at later processing, it can be pushed back down to where it should be, which also pushes any noise down too, offscale on the left.   I think no one in this thread has mentioned that.

Then (those less techie, less concerned with noise) picked up the notion that all our pictures ought be exposed to the right, as a concept of "correct exposure".    It is not of course, the histogram is NOT a light meter.  It is true that many pictures do have white or bright content (which should be high in the histogram), so it does often help, but for example, the proverbial "black cat in a coal mine" picture obviously should not.  The histogram has no clue where stuff should be, it only shows what result you got, good, bad, or ugly.  We have to decide if it is where it should be, which frankly, seems better done in the JPG image on the rear LCD.

But if checking the histogram (I do too), at least look at the RGB histogram, and ignore the single gray luminosity histogram, which is useless regarding exposure.  
The ONE THING the RGB histogram does show is if there is any clipping.


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## table1349 (Feb 9, 2014)

Would one of you Hijack Masters mind signing my copy of your training manual??:mrgreen:


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## WayneF (Feb 9, 2014)

gryphonslair99 said:


> Would one of you Hijack Masters mind signing my copy of your training manual??:mrgreen:




No, sorry, I think you are an imposter, who has not even participated in this thread, except for two flamboyant tries to attract attention to yourself.   

Seems to me this thread has stayed on track much better than most six page threads.


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## Ysarex (Feb 9, 2014)

WayneF said:


> Ysarex said:
> 
> 
> > I didn't say Adobe (or whatever Raw editor) was showing me a histogram of the Raw data. You're making false assumptions. I said, "Later in the computer I can see histograms of my raw data before I process it to a final RGB photo..."; see illustration below.
> ...



I think you're still failing to read the words I wrote and understand what I said. I don't know what "it" is in your second sentence that is always showing the RGB photo and never shows a histogram of raw data. That's between you and "it." *I said I do examine histograms of my raw data* and I showed you an illustration of raw data histograms. I'll show it to you again since it seems you missed it the first time. You might want to read the first line in that illustration where it says: RAW DATA HISTOGRAM.


View attachment 66301

You just previously told me, "No, Adobe (or whatever Raw editor) is not showing a histogram of the Raw data.  Nothing does." Obviously you're wrong -- something does. You're looking at raw data histograms right now in the accompanying illustration.

I never did complain before about being unable to see raw data histograms since of course I look at them all the time. I understand I can't get them on the camera, but I'm OK with that since I do get them when I examine my raw files on the computer.



WayneF said:


> > So I guess I do think the sensor raw capture is my "real data" and I do examine it carefully all the time to make sure I'm getting the best possible exposures. It would be nice if I could do that in the field but I'm happy with a process where I review my "real data" later and use that review to inform my work behind the camera. For me it's a more precise method than relying on the Red Green and Blue histograms displayed on the camera which we know have been interpreted by the camera processing software and do not directly represent my "real data."
> 
> 
> 
> Well, the RGB histogram is as good as it gets.  It works out really well in practice.  If unsatisfactory, go with the alternative I guess  (which the only alternative is shooting JPG).



No, no and no. On the camera the RGB histogram is as good as it gets from the camera manufacturer. There is UniWB (which I don't like and don't use) but it is an option. Checking the RGB histogram works out really well for you in practice -- well that's your practice. I just finished showing you another alternative which is to examine the raw histograms later as a way to test and inform your practice exposing the sensor when you're behind the camera -- an alternative without shooting JPEG.



WayneF said:


> > This thread began with a question about ETTR. To practice ETTR you need a way to examine the raw data as directly as possible to assess how you're exposing the sensor. Looking at data derived from the camera processed JPEG (camera manufacturer histograms of whatever flavor) is indirect and although it may be useful and possible to interpolate from that information it's off mark to suggest that it's anywhere near the "real data."
> 
> 
> 
> ...



Absolutely wrong. The RGB histogram shows if there is any clipping in the camera processed JPEG. That does not mean there is clipping in the raw file since we already know now that you were wrong to claim the RGB histogram shows us the "real data."

Joe


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## table1349 (Feb 9, 2014)

WayneF said:


> gryphonslair99 said:
> 
> 
> > Would one of you Hijack Masters mind signing my copy of your training manual??:mrgreen:
> ...



Perhaps you should re-familiarize with Post #1 and Post #53 by the OP and then look at #40 & #41.  The OP seems to have gotten an answer to their question in their thread and have left the building by page 4.


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## unpopular (Feb 9, 2014)

I think that there is a huge degree of misunderstanding about the histogram. It's important to remember that we didn't even have this option until digital came along - and still we managed to get satisfactory exposure somehow.

While it is true that the RGB histogram from the in-camera conversion is inaccurate, I have not found it to be so inaccurate that it's not useful, at least not in immediately telling me if I metered off the wrong region, and naturally, it's going to be conservative since conversion is a destructive process (you can't add detail to the jpg after all).

But overall, I do agree what has been said, understanding and trusting the meter is going to be much more fruitful than chimping around with the histogram.

One place I do use the histogram is to determine the quality of data recorded. As some of you know I expose for the hilights, and 95% of the time this works well. Where it does not is in low contrast scenes that should be rendered across a wide range of tones (i.e. subjects in shadow) where the bulk of the data is crammed up against the upper fifth of the tonal range, and practically nothing is recorded below the middle. In such instances it is better to expose to place Zone IX a little bit lower on the histogram and apply an S-Curve such that the shadows do not need to be stretched across tarnation.


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## WayneF (Feb 9, 2014)

Ysarex said:


> I think you're still failing to read the words I wrote and understand what I said. I don't know what "it" is in your second sentence that is always showing the RGB photo and never shows a histogram of raw data. That's between you and "it." *I said I do examine histograms of my raw data* and I showed you an illustration of raw data histograms. I'll show it to you again since it seems you missed it the first time. You might want to read the first line in that illustration where it says: RAW DATA HISTOGRAM.



Oops!  You're right of course, I get it now.   I was skimming and not paying enough attention.  Sorry.  That was an unexpected surprise, far from main stream, and  I have never bothered to go those extra steps, because frankly, it seems pointless to me, unnecessary at best.  Different strokes though, good luck with it.



> Absolutely wrong. The RGB histogram shows if there is any clipping in the camera processed JPEG. That does not mean there is clipping in the raw file since we already know now that you were wrong to claim the RGB histogram shows us the "real data."



My entire point then was that the single gray luminosity histogram DOES NOT SHOW REAL DATA (or clipping for the most part).  And the RGB histogram is the simple alternative, and in comparison, of these choices in the camera, yes, I do call that the real data.    You've taken it to another level outside the camera, that, sorry, but I am not interested in.  

Clipping is not a difficult situation to recognize. We do know about the clipping, it leaves data stacked up at 255.      It is not always that bad, sometimes it is done intentionally (with care) to improve contrast.   But as to correcting it, recognizing it in the camera is what seems important - it would be too late if later in your raw tools.  We are going to have to make the same shifts later, so even though it does not affect the Raw file, just set the camera WB more correctly for the final goal (at least to Auto), and it will be a similar operation, and should not be much issue.

 And if some situation is considered critical (probably involving Daylight red shifting), you can always just back off a bit, and put it back later in the Raw editor.  If you have to always push the limit, there will be surprises.


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## apaflo (Feb 9, 2014)

unpopular said:


> But overall, I do agree what has been said, understanding and trusting the meter is going to be much more fruitful than chimping around with the histogram.



The histogram helps show exactly what the meter is measuring.  Meter's aren't wrong, but photographers commonly haven't enough clue what the meter has measured and therefore get unacceptable results because they trusted that the measurement accurately described something it didn't measure.

It's "chimping around with the histogram" that can make the meter useful.



unpopular said:


> One place I do use the histogram is to determine the quality of data recorded. As some of you know I expose for the hilights, and 95% of the time this works well. Where it does not is in low contrast scenes that should be rendered across a wide range of tones (i.e. subjects in shadow) where the bulk of the data is crammed up against the upper fifth of the tonal range, and practically nothing is recorded below the middle. In such instances it is better to expose to place Zone IX a little bit lower on the histogram and apply an S-Curve such that the shadows do not need to be stretched across tarnation.



Your lead into that is quite correct, but the example you give is not.  Place Zone IX at just less than clipping, and in post processing place it a bit lower (into Zone IX when no texture is require or into VIII to get visible texture).  

Or in other words, if something should be at about 245 in a JPEG image, expose it at 254 if you wish.  Everything brighter than that will be clipped and lose all detail.  But in post processing the brightness should be dropped to 245 or less, which will allow the detail to be visible.  Areas that in the scene were brighter will still be clipped, whether at 255 or when reduced to 246.   Note that basically all levels greater than 245 in a JPEG, whether printed or viewed on a computer monitor, will lack detail. They may not be totally into clipping, but close enough that it makes little difference.

Just originally exposing with Zone IX lower on the histogram merely loses dynamic range, actually causing the shadows to potentially need stretching.


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## unpopular (Feb 9, 2014)

Well. Histogram reflects what has been recorded (and in most cases, converted)... but that's splitting hairs.

As for placement, I still maintain to place the outer edge of the tonal range (zone IX) to the outer limits of the histogram (245-250, in 8-bit scale) and just let them sit there, pulling shadows while leaving the hilight mostly alone. The reason for this is because you'll record deeper into the shadows, permitting better control over local contrast on the low-end. 

But, keep in mind that my eye also tends to very soft contrast.


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## Ysarex (Feb 9, 2014)

WayneF said:


> Ysarex said:
> 
> 
> > I think you're still failing to read the words I wrote and understand what I said. I don't know what "it" is in your second sentence that is always showing the RGB photo and never shows a histogram of raw data. That's between you and "it." *I said I do examine histograms of my raw data* and I showed you an illustration of raw data histograms. I'll show it to you again since it seems you missed it the first time. You might want to read the first line in that illustration where it says: RAW DATA HISTOGRAM.
> ...



OK, making some progress. Thanks for the good luck wishes.



WayneF said:


> > Absolutely wrong. The RGB histogram shows if there is any clipping in the camera processed JPEG. That does not mean there is clipping in the raw file since we already know now that you were wrong to claim the RGB histogram shows us the "real data."
> 
> 
> 
> ...



So, I know what clipping is. And you just said, "The ONE THING the RGB histogram does show is if there is any clipping." That's not accurate. The RGB histogram will show clipping if it's present in the camera processed JPEG. That camera JPEG might be your "real data" but it's not mine. Clipping in the camera JPEG is not an adequate indication of clipping in the raw file especially if you're going to leave the camera set to auto WB as you advocate. In high contrast lighting conditions the camera JPEG processor will clip the highlights long before they're clipped in the raw file.

Joe


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## sk66 (Feb 9, 2014)

I don't really see the point in checking the raw file histograms... it's not something you can "work with." Maybe to get an understanding of how the camera histograms relate to the raw data so that you can more accurately interpret the camera histograms. But that's not much different than just working with the files in your conversion software and determining what's there (recoverable) that wasn't shown in the camera.


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## sk66 (Feb 9, 2014)

WayneF said:


> ETTR seems a mixed bag.  The original idea was with techies, pushing everything as far right as it will go (which is possibly overexposure, but not clipping), so that at later processing, it can be pushed back down to where it should be, which also pushes any noise down too, offscale on the left.   I think no one in this thread has mentioned that.


The idea is that data in a raw file is not dispersed linearly and that most of the data (bits) recorded is at the high end. By pushing the exposure to the high end (without clipping) you thereby record the most usable data... and then push it back left/down for "proper exposure."
For me, it's too much hassle for "gains" I don't see the need for. (and often I don't see them as being a reality) IME, and for what I do, protecting highlights is of more value.

A lot of the DR increases in modern sensors are in the shadow areas... areas that are not of a lot of use generally, but the same areas that ETTR was meant to benefit.


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## unpopular (Feb 9, 2014)

It's about increasing the amount of signal over noise.

But in practice, for me anyway, it's about capturing the widest possible amount of useable ("not-noisy") data so that I can make choices about how it should be rendered in the end photograph. By providing sufficient headroom I have more information to choose how it best reflects the scene.

The problem with ETTR has always been it's arbitrary implementation. The technique is sound, and is pretty much the same in concept as The Zone system.


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## Ysarex (Feb 9, 2014)

sk66 said:


> I don't really see the point in checking the raw file histograms... it's not something you can "work with." Maybe to get an understanding of how the camera histograms relate to the raw data so that you can more accurately interpret the camera histograms. But that's not much different than just working with the files in your conversion software and determining what's there (recoverable) that wasn't shown in the camera.



It's information. You noted earlier that the JPEG histograms displayed on the camera are not accurate -- you're right, and as you also noted UniWB is a hassle if not a kludge. I'm not an ETTR fanatic but I do make exposures carefully with the goal of getting maximum value from my equipment. I learned over 40 years ago that you don't do anything important with untested equipment. Examining the raw histograms let's me precisely test my equipment. Because your raw converter is demosaicing the raw file and applying a tone curve and WB to the RGB data, the information you get there isn't as clean as looking at the raw files prior to demosaicing. It's not something I do with every photo, but I do run periodic checks on my equipment and at my age on myself to make sure everything is working.

Joe


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## sk66 (Feb 9, 2014)

Ysarex said:


> sk66 said:
> 
> 
> > It's not something I do with every photo, but I do run periodic checks on my equipment and at my age on myself to make sure everything is working.
> ...


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## Gavjenks (Feb 10, 2014)

> ETTR is of no value when shooting JPEG only, and the histogram is exactly what it should be.  It always very accurately shows data for the JPEG.


Orly?

I suppose these two images look about equally high quality to you?


Left: Image ETTR in jpeg only, then darkened in photoshop (random ACE hardware spray bottle on my desk)
Right: Image ETTL in jpeg only, then brightened in photoshop
So both were matched in lightness in the end, both suffered exactly 1 edit, both had their full curve in the range of the camera.

The ETTL is abysmal, the ETTR looks fine.

I did not touch the focus wheel or move an inch in between them, only changed the exposure compensation. Neither one clipped on either side of the histogram. And the one on the right was at 1/1600th of a second with a 135mm lens, so that is not motion blur (the other one was at 1/100 for comparison).





This is not a surprising result to me. The reason why ETTR works is equally as applicable to jpeg mode as it is to RAW: the file format has more data slots available in the higher stops of the histogram than in the lower ones, since number of lightness values per stop is an exponential function, not a linear one.

The bit depth (8bit jpeg or 16bit RAW, whatever) is irrelevant, because this fact is still true at any bit depth, and the number of values available at the left is going to be terrible no matter what your bit depth (maybe if you had a 500 bit camera or something, it would be fine, but nothing within the realm of reasonableness)


By the way, this image posted earlier is a *brilliant* depiction of why to ETTR (if light allows):

View attachment 66354
See how those bars get super spaced out over to the left? That's because the lower stops of the range ONLY HAVE 1, or 2, or 4 lightness values available to them. *Look at the numbers just below each graph*. That is as precise as the data gets to the left of the histogram! If you were to expose a narrow dynamic range image to the darkest (leftmost) 3 stops, your entire image would be posterized to *7* lightness values total, which would be absolutely horrendous. The spray bottle image above is almost that bad -- that's what ETTR looks like in RAW or JPEG.

Notice that to the right, though, the data comes in thick and plentifully. That's where you want your image to be. Not chopped up into the sparse wasteland of data on the left.  As far to the right as possible, where the most data is, short of clipping your highlights.

The rightmost stop in this image (for what I'm guessing is an 11 bit camera) has 1024 lightness values within it.  the leftmost has... 1. *Which of those sounds like where you want the bulk of your image to be?*


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## apaflo (Feb 10, 2014)

Gavjenks said:


> > ETTR is of no value when shooting JPEG only, and the histogram is exactly what it should be.  It always very accurately shows data for the JPEG.
> 
> 
> Orly?
> ...



They appear to be very poor quality images in terms of exposure and editing choices.



Gavjenks said:


> This is not a surprising result to me. The reason why ETTR works is equally as applicable to jpeg mode as it is to RAW: the file format has more data slots available in the higher stops of the histogram than in the lower ones, since number of lightness values per stop is an exponential function, not a linear one.



 That is true for a "linear" encoding scheme, which the RAW file is but the JPEG is not.  The RAW file has twice as many levels at each brighter stop.  A JPEG actually can encode 20 stops though only about 9 are useful. The 9th stop has 6 levels (which means it will appear posterized), the 8th has 7, then 11, then 14, then 19, then 27, 37, and 50 for the next to the brightest, while the brightest stop has still has only 69 levels.   Clearly there are not enough even in the brightest stop to allow significant expansion or compression, and in no case does any stop have twice the levels of 1 stop less.



Gavjenks said:


> The bit depth (8bit jpeg or 16bit RAW, whatever) is irrelevant, because this fact is still true at any bit depth, and the number of values available at the left is going to be terrible no matter what your bit depth (maybe if you had a 500 bit camera or something, it would be fine, but nothing within the realm of reasonableness)



But the reason it is not irrelevant is that with JPEG the number of values at the right is also terrible.  There just is no room for significant changes to brightness or contrast. 



Gavjenks said:


> View attachment 66354
> See how those bars get super spaced out over to the left? That's because the lower stops of the range ONLY HAVE 1, or 2, or 4 lightness values available to them. *Look at the numbers just below each graph*. That is as precise as the data gets to the left of the histogram! If you were to expose a narrow dynamic range image to the darkest (leftmost) 3 stops, your entire image would be posterized to *7* lightness values total, which would be absolutely horrendous.



Has anyone suggested doing that?

What is significant though, is that with a 14 bit RAW file (and clearly this is worse by 2 stops with a 12 bit RAW file), there are almost as many levels in the 8th stop of the RAW file as there are in the 1st stop of the JPEG file.  That is why  it isn't a good idea to try editing JPEG images to correct for any significant amount of exposure error.  Thus, ETTR is only valid for RAW files.


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## Gavjenks (Feb 10, 2014)

> They appear to be very poor quality images in terms of exposure and editing choices.


Obvious avoidance of the evidence is obvious.
This isn't a submission to an art gallery. It's a 2 minute's effort ETTR demo with junk on my desk. And it does that quite effectively.
And yes, *the whole point* is that one of them is a worse choice of exposure and editing choices. Whenever you don't ETTR, you're making a poor exposure and editing choice (unless you simply don't have the light or time to do so)



> That is true for a "linear" encoding scheme, which the RAW file is but the JPEG is not. The RAW file has twice as many levels at each brighter stop. A JPEG actually can encode 20 stops though only about 9 are useful. The 9th stop has 6 levels (which means it will appear posterized), the 8th has 7, then 11, then 14, then 19, then 27, 37, and 50 for the next to the brightest, while the brightest stop has still has only 69 levels. Clearly there are not enough even in the brightest stop to allow significant expansion or compression, and in no case does any stop have twice the levels of 1 stop less.


If you read carefully you will discover that I never claimed the JPEG has twice as many per stop there. I said that both formats have more slots as you go higher, that it is an exponential function, and that because of this, the logic of why you ETTR is applicable to both formats.


As you yourself just said, the lowest stops of JPEG are not as useful, because they lead to posterization. 
Which is a very succinct explanation of why ETTR matters in JPEG. So, thanks!




> Has anyone suggested doing that?


No nobody talks about exposing to the left, but I thought the logic was pretty obvious: it's a continuum. The further to the left you go, the more of the problem you have. ETTL is just the easiest extreme case to demonstrate and describe the problem.


In reality, yes, people either ETTR, or they leave the histo in the middle.  But the middle is still more to the left, and thus you are throwing data away.  And still quite a bit of it, too, depending on the image (low dynamic range images suffer more by comparison, since they could have been ETTR'ed that much more).




> What is significant though, is that with a 14 bit RAW file (and clearly this is worse by 2 stops with a 12 bit RAW file), there are almost as many levels in the 8th stop of the RAW file as there are in the 1st stop of the JPEG file. That is why it isn't a good idea to try editing JPEG images to correct for any significant amount of exposure error. Thus, ETTR is only valid for RAW files.


...wat


If you're shooting JPEG, *you don't have a RAW file*, so the number of levels per stop in RAW files is utterly irrelevant to you. RAW files obviously only matter to people who shoot RAW files. Those who do JPEG start out with only the levels in JPEGs, amongst which ETTR matters almost as much as for anybody else.

Also, it really isn't that bad to edit JPEGs to be DARKER, for the same reasons we are both talking about: you're starting out with more data than you need for your final image if you ETTR and then darken.  Massive posterization in JPEG editing primarily only arises when you have a dark image and you *BRIGHTEN *it (in other words, exposing to the left! Usually unintentionally).


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## WayneF (Feb 10, 2014)

apaflo said:


> They appear to be very poor quality images in terms of exposure and editing choices.
> 
> That is true for a "linear" encoding scheme, which the RAW file is but the JPEG is not.  The RAW file has twice as many levels at each brighter stop.  A JPEG actually can encode 20 stops though only about 9 are useful.



I think that is misleading (and not about ETTR and then backing it back off).  That is only about gamma of course (and is about any RGB image, not just JPG),  Gamma encodes RGB file data as approximately square root values, so yes, the result (in the file) has chart coordinates with more values of range, while encoded -but the data still has the same range, as in the linear original. 

 The data in our histograms does show these new gamma values (Not our real data, he he he).   But our video screens do not show it (only presents to our eyes a reproduction of our original linear data)

I have never understood why Poynton claimed this to be any range advantage for digital data (like you mentioned).   One, these are not New data values, not more values with more range in dark data, but just same tones (one for one) as we already had. But two, the really big deal, mainly because humans NEVER look at gamma data.  RGB is always decoded back to linear (one way or another, CRT losses or LCD software) before human eyes ever see it. We would not like looking at gamma data.  So it is always (hopefully) restored to be exactly same linear data as before.  The best possible result is absolutely no change. Anything else is an error.

I can see gamma was an advantage for analog TV broadcast, noise added during RF analog transmission was decoded back out (in some slight extent, lowest values, squared and separated more - something like ETTR in that respect).  But this is not applicable to digital data, since noise is not added in the file (and CRC is another issue for digital HDTV broadcast).  The standards still do gamma only for data compatibility (all RGB data in the world already has gamma in it - and for old CRT monitors too).

But gamma is just a confusion here, and I certainly do not see it as any argument for JPG.


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## Gavjenks (Feb 10, 2014)

> _That is true for a "linear" encoding scheme, which the RAW file is but the JPEG is not. _





> linear original.


*Nothing *is "linear" here... that's the whole point. Everything is exponential. Or in some cases some other things, but never linear.

Jpeg is not linear. The data slots available go up exponentially, roughly 1.35^(stop)
RAW is not linear. The data slots also go up exponentially, at 2^(stop)
Your brain/eyeballs are not linear. On average, they're about 2^(stop), though sensitivity rises more slowly than that in dark light and faster than that in bright light.
F stops are not linear. They go up at 2^(stop)
Histograms aren't linear. They go up at 2^(stop)
Theoretical maximum data available is not linear. Actual discrete information in photons goes up at 2^(stop)
Gamma adjustments on monitors are not linear. It's a power law function.

Gamma also has nothing to do with why you should expose to the right.
The reason is based on the fundamental quantum nature of light: 2 photons per second = 1 stop less than 4 photons per second = 1 stop less than 8 photons per second, etc.
8 photons is only 2 stops higher than 2 photons, yet it has 4x the data precision. So data density/precision goes up faster than stops do, thus you get the highest data integrity by recording image at the brightest levels your camera can handle.



It doesn't matter what technology they invent in the future, or how you crunch the numbers, or what formats you use.
Exposing to the right will *ALWAYS *forever and ever give you higher data precision than exposing to the middle, as long as photons remain quantized (which is presumably for the rest of the age of the universe)


By the way, ETTR is also valid logic in film photography (as it is to some extent in any photographic process possible): When you pull process film (overexpose, then underdevelop, i.e. ETTR), you increase the effective latitude / dynamic range of the film, allowing for greater detail / more data not being clipped like it otherwise would be in some shots.  It isn't used as often as in digital, because it's hard to aim the exposure just right without blowing the highlights when you don't have a histogram to fine tune in the field, and because film already usually has more latitude to work with in the first place, so it just isn't as often necessary.  But in certain scenes, it is sometimes done on purpose, and functions from the exact same concept: More silver grains in the film react at high exposure in a NON-LINEAR relationship to stops, and thus more data precision is possible by exposing to the right.


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## WayneF (Feb 10, 2014)

Gavjenks said:


> *Nothing *is "linear" here... that's the whole point. Everything is exponential. Or in some cases some other things, but never linear.



You should have stopped earlier. 

In video processing, linear is the word used to mean "before gamma encoding", and nonlinear means after gamma.  Because, all RGB video has gamma in it.



> RAW is not linear. The data slots also go up exponentially, at 2^(stop)



In the math sense, linear means that 2x change makes a 2x result change (instead of an exponential change).

Raw data is linear, in that math sense (because it has not yet been encoded in the video sense).   You seem to just be claiming that a 2x progression is not linear (x squared), but the data is.  We call 2x to be a stop (twice as much), but the only reason it is twice as much is because the data is linear. 

 Shutter speed is linear, ISO is linear.  So is aperture area, but fstop numbers are a circular area computation which is not numerically linear.

Raw data is linear (no gamma), but then RGB conversions have gamma, and are not linear.


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## Gavjenks (Feb 10, 2014)

Yes, in terms of actual raw luminance, it is linear.

But I'm not talking in terms of raw luminance, because humans don't see raw luminance, so why should we care about that? 
Our perception changes exponentially. We see twice as much light as "one linear step brighter" 
Our brains see things as if stops were linear.So what I mean is that there is not a linear relationship between human perception versus data value distribution, the two things that actually practically matter to us as practicing photographers.

Ideally, due to our perception, you would want an equal distribution of data values in each and every stop. That's the assumption people always intuitively make. And that's the assumption that is inherent in the concept of exposing to the middle.

Sorry for any confusion in terms. 




Regardless of what one labels "linear" or not from different rhetorical perspectives, though....
*Bottom line = exposing to the right still encapsulates more data than exposing to the middle (thus maximum editing latitude)*, which is the main issue of the thread, and the take-home message for practical photography purposes.


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## WayneF (Feb 10, 2014)

Gavjenks said:


> Yes, in terms of actual raw luminance, it is linear.
> 
> But I'm not talking in terms of raw luminance, because humans don't see raw luminance, so why should we care about that?
> Our perception changes exponentially. We see twice as much light as "one linear step brighter"



Yes, of course our human eyes do see linear light.  That is all there is to see, light is linear.

Our perception may not be, but our non-linear eyes obviously require that we see the original analog linear data (or a faithful reproduction), so our brain doing its thing won't think it was distorted.   

The original light is linear.  Our raw sensors are linear.  By definition.  Our RGB is encoded with gamma for other reasons, but it is always decoded back to linear before human eyes see it.  Linear is a pretty big deal.


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## Gavjenks (Feb 10, 2014)

Yes okay, so in some situations, you convert it to something else and then convert it back to the original again. And the incoming light is linear to your eyes. So what?
I still fail to see the point of what any of this has to do with the topic of the thread: exposing to the right.

Gamma in between, not gamma in between, brain eyes, whatever, you still get the most data precision by exposing to the right... 

The answer to the OP is yes regardless.


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## unpopular (Feb 10, 2014)

No. The light that the raw file records is exponential, but the data that represents the light is linear relative to one another. Linear relation is a mathematical fact and not subject to rhetoric.

A lot goes on behind the closed doors of your RAW processor. I have a raw processor that permits no gamma correction be applied to any of the channels (uni-WB with a gamma set to 1.0).

The results are very dark and overwhelmingly green. ETTR permits the gamma correction not need to be applied as severely to get the desired result. In most RAW processors this is "undone" by a RAW curve adjustment, in RPP it can be set firsthand - in practice it may not really matter, though it would depend on the processing pipeline. As for the native color balance, I believe that a magenta filter would be beneficial, though I haven't tried it yet and cannot say to what extent IQ would be impacted.

I do know is that a daylight correction pushes the red channel significantly, WAY more than what most of us would be comfortable with. So my point is that no matter how you look at it, your camera sensor sees the world very differently and that the raw processor must do all sorts of funny business to make us believe that it does.


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## Gavjenks (Feb 10, 2014)

unpopular said:


> No. The light that the raw file records is exponential, but the data that represents the light is linear relative to one another. Linear relation is a mathematical fact and not subject to rhetoric.
> 
> A lot goes on behind the closed doors of your RAW processor. I have a raw processor that permits no gamma correction be applied to any of the channels (uni-WB with a gamma set to 1.0).
> 
> ...



None of which changes the answer to the OP, either, which is still "yes, ETTR if possible with time constraints and without going into too slow of a shutter speed"

Anybody can try it themselves and go take a photo exposed to the right, left, center, edit them to be the same exposure, and compare to see the obvious and sometimes massive (in the case of low dynamic range scenes) quality differences.


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## runnah (Feb 10, 2014)

I will have you all refer to this chart please.




I rest my case.


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## sk66 (Feb 10, 2014)

I prefer this one:


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## TWright33 (Feb 10, 2014)




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## runnah (Feb 10, 2014)

sk66 said:


> I prefer this one:




That is good. This is my all time favorite.


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## apaflo (Feb 10, 2014)

Gavjenks said:


> > _That is true for a "linear" encoding scheme, which the RAW file is but the JPEG is not. _
> 
> 
> 
> ...



 My appologies if I used common technical terminology that you are not familiar with.  In fact my statement was *precisely* correct.

 Linear encoding refers of course to a linear gamma curve.  Virtually all RAW data files use linear encoding.  And virtually *everyone* who is familar with digital data encoding is aware of that meaning and uses it consistently and commonly. 

Various digital encodings have different advantages.  Gamma compression of digitally encoded analog data is commonly used (meaning photography is hardly unique) to preserve a higher SNR at the expense of dynamic range while using fewer bits.  The most common example (but perhaps not typically realized by users) is the use Mu-Law gamma encoding of voice traffic in the Public Switched Telephone Network (PSTN).

Some good sources of information, for photographers:

Understanding Gamma Correction
Learn about RAW, JPEG, and TIFF with the digital photography experts at Photo.net.

A more technical article:

Linear Encoding


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## Gavjenks (Feb 10, 2014)

I think it's abundantly clear by now what everybody meant, apaflo. You're talking in a digital data encoding language, where apparently linear refers to actual luminance.
I'm talking in photography language, where exponential increases in actual physical light are usually referred to using linear language (+/- EVs / stops).

The miscommunication was cleared up a page ago, and no matter which community's language you use, the answer to the OP's question is the same, so who cares?


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## TWright33 (Feb 10, 2014)

apaflo said:


> Gavjenks said:
> 
> 
> > > _That is true for a "linear" encoding scheme, which the RAW file is but the JPEG is not. _
> ...





Gavjenks said:


> I think it's abundantly clear by now what everybody meant, apaflo. You're talking in a digital data encoding language, where apparently linear refers to actual luminance.
> I'm talking in photography language, where exponential increases in actual physical light are usually referred to using linear language (+/- EVs / stops).
> 
> The miscommunication was cleared up a page ago, and no matter which community's language you use, the answer to the OP's question is the same, so who cares?


View attachment 66423


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## apaflo (Feb 10, 2014)

Gavjenks said:


> I think it's abundantly clear by now what everybody meant, apaflo. You're talking in a digital data encoding language, where apparently linear refers to actual luminance.
> I'm talking in photography language, where exponential increases in actual physical light are usually referred to using linear language (+/- EVs / stops).
> 
> The miscommunication was cleared up a page ago, and no matter which community's language you use, the answer to the OP's question is the same, so who cares?



What is clear is that you didn't understand what gamma compression, as used in a JPEG format, is or how it compares to the linear encoded format used by RAW files.

I have seen no indication yet that you've learned a thing either.  None of this is "in photography language" or "linear language" or some mysterious "digital data encoding language".  Nothing appears to have "cleared up" at all!

If you will slow down and not make such an effort at obstinance, and try to learn something about how all of these things interrelate to each other, it actually does become easier to comprehend once it is properly organized.  I actualy think that trying to understand the value of gamma compression is more difficult for people who are photographers and have little other exposure to digital data.  It's an abstraction that makes sense otherwise, but that abstraction is hard to work with when the data is literally displayed visually.


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## pixmedic (Feb 10, 2014)

I think this discussion has gone way off track from the OP's original question. 
I believe gavjenks has answered that question as much as it needs to be in the context of the original question.


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## pixmedic (Feb 10, 2014)

In case anyone was wondering...
I locked the thread because a lot of posts were getting reported. A LOT. Plus, things had started to get personal which never ends well. The OP has been gone for a bit and had long since had their question answered.

If anyone wants to rehash the "discussion" that encompassed the thread, they are more than welcome to start a new thread on it.

Sent from my SM-N900P using Tapatalk


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