# HSS (High-Speed Sync) and image quality



## syndicatedshannon (Jan 2, 2014)

I definitely don't want to restrict my daylight aperture with the off-camera flash equipment I'm buying. As you know, most current high-end consumer DSLR cameras have a maximum flash-sync shutter speed of about 1/250, meaning f/stops necessarily over 10 in daylight. So, I was doing some research on HSS.

I found these graphs of light amplitude from Canon HSS setups:






It looks like the amplitude is inconstant enough to cause some banding at the expected resolutions. Is that true?

Are there flash units that have constant-duration adjustable power output, without that charge-bounce symptom? If so, what keyword/distinction would I look for when purchasing?


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## lennon33x (Jan 2, 2014)

syndicatedshannon said:


> I definitely don't want to restrict my daylight aperture with the off-camera flash equipment I'm buying. As you know, most current high-end consumer DSLR cameras have a maximum flash-sync shutter speed of about 1/250, meaning f/stops necessarily over 10 in daylight. So, I was doing some research on HSS.
> 
> I found these graphs of light amplitude from Canon HSS setups:
> 
> ...



What kind of lights/strobes are you using?


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## syndicatedshannon (Jan 2, 2014)

I have one Canon 600ex, but was looking to buy a couple more devices with RF. Preferably significantly less expensive, non-vendor-specific, fairly portable and versatile, with a few modifiers. I asked my first question about that here yesterday.


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## syndicatedshannon (Jan 2, 2014)

And sorry about the embedded photos, I didn't realize they'd lose their URL. The first is from PocketWizard and the second is from Canon Speedlites and high-speed sync - Bob Atkins Photography


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## lennon33x (Jan 2, 2014)

I came across a similar issue. I ended up buying a Triopo speedlight, which is great, but it is the light that restricts your HSS capabilities. I have an Pixel King/Opas trigger system and Neewer strobes. What I found out is that with that specific trigger system, I can utilize my Neewer strobes (cheap knock off brand, but does the job well) because of the flash duration. I actually capture the tail end of the flash. I would focus on obtaining flashes that have HSS capabilities (I'm not sure about the 600 ex). I think Yongnuo 565EX is HSS; pretty comparable brand and is worth it (from what I heard). 

Your other option is an ND filter. It's a cheaper route, but depending on the quality of the glass, you could lose some IQ. 

But focus on the lights first, and then work backward.


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## lennon33x (Jan 2, 2014)

syndicatedshannon said:


> As you know, most current high-end consumer DSLR cameras have a maximum flash-sync shutter speed of about 1/250, meaning f/stops necessarily over 10 in daylight.



And my understanding is that most DSLRs have this limitation; not just high-end DSLRs. I had a Rebel T3 that was at 1/250, and my 5D (classic) is 1/200. The EOS 1D has 1/500, but all other features of the camera are so obsolete (i.e. 4 MP, 1.3 crop factor etc.)


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## syndicatedshannon (Jan 2, 2014)

Great point on the ND filter, reavesce. I would certainly be willing to buy a few Yongnuo 565EX. I wonder if vendor-specific HSS isn't really the best way to go, though. I guess my question was really mainly about HSS quality. Also, could you explain what you mean by the flash duration on your Neewer + trigger? Are you talking about this: http://www.youtube.com/watch?v=MUwfwFYl2MY#t=330


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## lennon33x (Jan 2, 2014)

When you say vendor-specific, do you mean Canon with Canon?


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## Derrel (Jan 2, 2014)

You might find that in really bright lighting conditions, high-speed flash synch produces less-than-optimally-sharp images on moving subjects...even relatively slow-moving people can exhibit blur from the stroboscopic flash output. I shot some portraits a couple summers ago on a beach at 1/2000 second with a VERY high-resolution 200mm prime lens...and the girl's face was blurry, where the ambient light + the flash combinedNikon FPS flash output combined.

I've not seen banding,m but I have seen what I call "ghosting", which is an old term applied to the faint double-line imaging characteristic of an image that has a narrow delta between flash + ambient.


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## rambler (Jan 2, 2014)

I do not have my manual with me, but I remember that my Nikon D7000 has a way to over-ride the max. sync speed of 1/250.  Something was lost when one did this, but I cannot remember that either!


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## Mach0 (Jan 2, 2014)

rambler said:


> I do not have my manual with me, but I remember that my Nikon D7000 has a way to over-ride the max. sync speed of 1/250.  Something was lost when one did this, but I cannot remember that either!



I think to 1/320 tops without any brand specific ttl capable wireless set up. My d700 is the same and my d90 you can enable auto FP as well.


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## Robin Usagani (Jan 2, 2014)

600RT is your best bet.  Buying triggers that can do HSS arent cheap either.  It is a better spending if you buy 600RTs instead.  That way you wont have cables or extra stuff dangling around.  If 600RT isnt strong enough you can put several of them together.


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## lennon33x (Jan 2, 2014)

Robin Usagani said:


> 600RT is your best bet.  Buying triggers that can do HSS arent cheap either.  It is a better spending if you buy 600RTs instead.  That way you wont have cables or extra stuff dangling around.  If 600RT isnt strong enough you can put several of them together.



Neewer strobe - $50
Opas receiver - $50
King transmitter -$100
HSS up to 1/8000. 

That's my setup. Granted it's not Profoto or ABs, it does a great job. 

I would highly consider an Alienbees or Einstein at that price point of a 600RT. If the OP wants to save cash, going directly to the high end speedlight may not be the way to go.


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## pixmedic (Jan 2, 2014)

Yongnuo 622 triggers do TTL and HSS and are $80-ish a pair.  Ive been extremely happy with mine with my nikon and yongnuo flashes.  I dont actually use HSS very often, but i like having the ability to do so.

Yongnuo 568ex flashes do HSS and TTL and are $180 brand new.  I have a few of them and they have been great.


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## Mach0 (Jan 2, 2014)

reavesce said:


> Neewer strobe - $50 Opas receiver - $50 King transmitter -$100 HSS up to 1/8000.  That's my setup. Granted it's not Profoto or ABs, it does a great job.  I would highly consider an Alienbees or Einstein at that price point of a 600RT. If the OP wants to save cash, going directly to the high end speedlight may not be the way to go.



Post pics. I would like to see your strobe syncing that high. Not trying to stir up anything, I'm genuinely curious.


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## lennon33x (Jan 2, 2014)

Mach0 said:


> Post pics. I would like to see your strobe syncing that high. Not trying to stir up anything, I'm genuinely curious.



Ok. What do you want pics of?


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## EIngerson (Jan 2, 2014)

pixmedic said:


> Yongnuo 622 triggers do TTL and HSS and are $80-ish a pair.  Ive been extremely happy with mine with my nikon and yongnuo flashes.  I dont actually use HSS very often, but i like having the ability to do so.
> 
> Yongnuo 568ex flashes do HSS and TTL and are $180 brand new.  I have a few of them and they have been great.



Awesome, I just ordered a 4 pack of the 622's right before reading this.


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## syndicatedshannon (Jan 2, 2014)

Thank you Derrel for responding to the fundamental technical question, and thanks to everyone else for the product recommendations.

Thank you Mach0 for following up on reavesce's equipment suggestion. Looking forward to the reply.

Robin Usagani, I'm not looking to start a debate, but I am looking to keep my expenses down until I better understand what I need (e.g. maybe buying studio lights). Can you offer any words of warning about pixmedic's suggestion (of Yongnuo 622 triggers and 568ex flashes)? I'm considering this. If it's a matter of life expectancy as I've been reading, I don't care much at this stage, but if it's a functionality or image quality issue I'd be more likely to avoid them.


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## lennon33x (Jan 2, 2014)

syndicatedshannon said:


> Thank you Derrel for responding to the fundamental technical question, and thanks to everyone else for the product recommendations.  Thank you Mach0 for following up on reavesce's equipment suggestion. Looking forward to the reply.



Realistically I won't do it until tomorrow...it's about bedtime for my twins. But I'll get it done


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## pixmedic (Jan 3, 2014)

Mach0 said:


> reavesce said:
> 
> 
> > Neewer strobe - $50 Opas receiver - $50 King transmitter -$100 HSS up to 1/8000.  That's my setup. Granted it's not Profoto or ABs, it does a great job.  I would highly consider an Alienbees or Einstein at that price point of a 600RT. If the OP wants to save cash, going directly to the high end speedlight may not be the way to go.
> ...



forget pics...how about a crappy P&S video demonstrating the HSS and TTL capabilities of the 622n triggers with a YN568EX flash and a SB700?


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## Mach0 (Jan 3, 2014)

pixmedic said:


> forget pics...how about a crappy P&S video demonstrating the HSS and TTL capabilities of the 622n triggers with a YN568EX flash and a SB700?  YouTube Link: http://www.youtube.com/watch?v=quDckBzVBR8



Hahaha 
It will be nice to see how some folks have combatted it. hSS or ND filters are great outside. I use nd filters but the view finder gets soooo dark lol.


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## syndicatedshannon (Jan 3, 2014)

Thank you pixmedic. The video is very appreciated.

I didn't understand Mach0's reply about how people have "combatted it", but I wonder if you could post the photo you took here. Or, perhaps just verbally describe what you mean when you say (in the youtube video) the photo quality wasn't great. As you know, we can't see what's going on in the point-and-shoot video of the viewfinder . Was the flash quality good, but the composition bad?

Thank you!


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## pixmedic (Jan 3, 2014)

syndicatedshannon said:


> Thank you pixmedic. The video is very appreciated.
> 
> I didn't understand Mach0's reply about how people have "combatted it", but I wonder if you could post the photo you took here. Or, perhaps just verbally describe what you mean when you say (in the youtube video) the photo quality wasn't great. As you know, we can't see what's going on in the point-and-shoot video of the viewfinder . Was the flash quality good, but the composition bad?
> 
> Thank you!



I was shooting in low light. HSS flashes are weaker, so all the pictures I took for the demonstration were underexposed. 
the video wasn't meant to show taking a _*good*_ picture using HSS, but rather, to show the HSS and TTL functions of the yongnuo 622n triggers with the YN568EX and SB700 flashes on and off camera.


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## Mach0 (Jan 3, 2014)

syndicatedshannon said:


> Thank you pixmedic. The video is very appreciated.  I didn't understand Mach0's reply about how people have "combatted it", but I wonder if you could post the photo you took here. Or, perhaps just verbally describe what you mean when you say (in the youtube video) the photo quality wasn't great. As you know, we can't see what's going on in the point-and-shoot video of the viewfinder . Was the flash quality good, but the composition bad?  Thank you!



Whoops that was a half arsed reply since I'm at work. I meant combatted the mid day sun. My bad!


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## Mach0 (Jan 3, 2014)

pixmedic said:


> I was shooting in low light. HSS flashes are weaker, so all the pictures I took for the demonstration were underexposed. the video wasn't meant to show taking a good picture using HSS, but rather, to show the HSS and TTL functions of the yongnuo 622n triggers with the YN568EX and SB700 flashes on and off camera.



I gotta do some research and see what set of pw's or similar allow the delay of firing the flash so I can use Mono's outside and auto FP. 
Thanks for jogging the memory.


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## lennon33x (Jan 3, 2014)

Mach0 said:


> reavesce said:
> 
> 
> > Neewer strobe - $50 Opas receiver - $50 King transmitter -$100 HSS up to 1/8000.  That's my setup. Granted it's not Profoto or ABs, it does a great job.  I would highly consider an Alienbees or Einstein at that price point of a 600RT. If the OP wants to save cash, going directly to the high end speedlight may not be the way to go.
> ...




This is evening.
This is ISO 800, f/4, 1/3200



This is ISO 800, f/1.8, 1/8000



I had to crank my ISO up since it was becoming dusk.


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## Derrel (Jan 3, 2014)

reavesce, would it be possible to list the exact model number and "type" of gear you have? I am not sure about the Neewer strobe; it is an on-camera type of shoe-mount flash unit, right? Neewer is a brand sold, I guess off of e-Bay,and mostly in the UK-Taiwan-European Union areas? Or am I misinformed? I think it would be really useful information to know exactly what models of stuff you've found to work, so others might use this thread as a real resource. The Opas and KIng units, again, not sure what 'exact' models or series you are using, and so on. Thanks!


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## Mach0 (Jan 3, 2014)

Derrel said:


> reavesce, would it be possible to list the exact model number and "type" of gear you have? I am not sure about the Neewer strobe; it is an on-camera type of shoe-mount flash unit, right? Neewer is a brand sold, I guess off of e-Bay,and mostly in the UK-Taiwan-European Union areas? Or am I misinformed? I think it would be really useful information to know exactly what models of stuff you've found to
> 
> work, so others might use this thread as a real resource. The Opas and KIng units, again, not sure what 'exact' models or series you are using, and so on. Thanks!



He's using a neewer monolight.


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## lennon33x (Jan 3, 2014)

I'm using the following:
Canon 5D Mk I
EF 50mm 1.8 II
Pixel King transmitter mounted to the camera hot shoe
Pixel Opas transceiver acting as the receiver connected via PC sync to the strobe
Neewer C-250 monolight (no modifier used on this setup)

I also use a Neewer C-180 (the numbers designate the watts of the strobe). I don't use the Pixel King receiver if I'm using HSS. It isn't compatible with the system I use. I'm not sure WHY that particular receiver doesn't work but I figured out how to do the workaround.


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## syndicatedshannon (Jan 5, 2014)

Thanks again for the help. I just wanted to report back a little bit of research on high-speed flash operation.

*Variable-duration vs. Variable-voltage
*These two types of flash can typically be distinguished as follows:

*Variable-duration flash*
Small-battery powered flash (power control via flash duration is more energy-efficient, and so usually used with batteries)
Handheld and camera-mounted speedlites (these are typically small-battery powered, just due to physical dimensions)
Xenon gas-filled flashes (xenon-filled flashes are more efficient and work at lower voltages, and are used for increased battery life)
IGBT controlled flashes (insulated-gate bipolar transistors offer high-efficiency high-speed current switching in current small electronics)

*Variable-voltage flash*
Studio monoflash units
Voltage-controlled studio strobe
Units with integrated modelling lamps
Wall-powered flash


*How this affects your image*
Flash color and duration is affected by the type of flash and its configured power output setting. Here is a very useful reference for understanding that: Paul C. Buff, Inc. - Flash Duration

Both types of flashes exhibit *color changes* when power is adjusted. However, that change is different for each. One reason is the materials used for the flash. Another, possibly non-intuitive reason is this: A variable-duration flash trims the trailing end of the output (when the capacitor has already discharged and the voltage has diminished) as necessary to reduce total light output. This causes the average flash voltage to actually be higher as power decreases of a variable duration flash. A variable-voltage flash unit diminishes the voltage for the entire duration of the flash, but also causes the the voltage to be more consistently distributed through the flash.

Both types of flashes also change the *visible duration* as power is adjusted. Variable-duration flashes obviously reduce duration with reduced power, although not at a linear rate - most of the power is spent early. Variable-voltage flashes result in a "slower" flash at lower power, because the initial output is dampened (the waveform is smoothed) as voltage is reduced. Thus a greater percentage of the power is spent late in the flash. The reason for this can also be seen in the photo above.


*Relationship to sync-speed and "HSS"*
At *full power*, total flash duration for both types of flash are commonly equivalent to exposure times from 1/400 - 1/600 (although most of the light has already been emitted by 1/2000). A Canon 580EX II (variable-duration) flash set to *1/128 power* will only last a total of about 1/60,000 of a second. A similar Yongnuo flash is about twice as fast. (



)

Typical camera "max flash-sync speed" (the shortest exposure for which the leading shutter has finished opening for a useful period of time before the trailing shutter begins to close) ranges from 1/150 - 1/350. This duration and shutter "curtain speed" is slightly slower than the typical flash duration, by design. Making the shutter open and close operations more "instantaneous" to raise this sync-speed is not tremendously advantageous in typical consumer equipment. As you have seen above, flash devices are also fairly variable in function beyond these speeds - they have variable output pattern by device manufacturer and model, and that output pattern is asymmetric. As a result, for a conventional flash to be consistent from photo to photo and from image top to bottom (or left to right), the entire flashpower must be spent while the shutter is fully open.

However, with "high-speed-sync" (HSS) flashes, the flash is actually pulsed rapidly over the entire duration the shutter is open AND partially open.

Unfortunately, this reduces maximum flash power for two reasons:
1) Now, rather than the entire flash output reaching the sensor, only a portion of the sensor is revealed to the flash at any point. The shutter speed is now modifying flash power.
2) The "pulsing" action typically increases total duration to cover the entire time from shutter open to shutter close. This reduces the flash output at any given point (the flash hardware is generally not designed to survive or be electronically capable of full power operation for these longer durations)
This PocketWizard wiki image shows a 600EX-RT output in HSS mode: 


*High speed without HSS*
Apparently, although I haven't confirmed this, at very high shutter speeds, another method (avoiding HSS) is to envelop the entire shutter operation with the flash duration, by setting a variable-duration flash to full power. Flash distance from the subject is then used to vary exposure. I'm not sure why flash output waveform isn't visible as a decrease in light across the image (i.e. "shutter creep"), since higher shutter speeds don't actually increase the curtain speed but instead narrow the opening that passes over the sensor. Here is a video that I don't fully understand: Breaking The 1/250s Sync-Speed Trick! - YouTube

If you understand that, information would be appreciated. I guess I'd be curious to see if his image looked different if he held the camera upside-down here.

As a final note, remember an alternative to high-speed may be to use an ND filter, if your goal for high-speed is simply to preserve bokeh in a bright scene.


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## lennon33x (Jan 5, 2014)

syndicatedshannon said:


> *High speed without HSS*
> Apparently, although I haven't confirmed this, at very high shutter speeds, another method (avoiding HSS) is to envelop the entire shutter operation with the flash duration, by setting a variable-duration flash to full power. Flash distance from the subject is then used to vary exposure. I'm not sure why flash output waveform isn't visible as a decrease in light across the image (i.e. "shutter creep"), since higher shutter speeds don't actually increase the curtain speed but instead narrow the opening that passes over the sensor. Here is a video that I don't fully understand: Breaking The 1/250s Sync-Speed Trick! - YouTube
> 
> If you understand that, information would be appreciated. I guess I'd be curious to see if his image looked different if he held the camera upside-down here.
> ...


.

I watched the video, originally and had posted on a similar issue on another thread. The video, in general is not very helpful. It just explains that in order to combat banding due to the rapid closing of the second curtain that you need to have either a.) a longer flash duration to "beat" the second curtain, or b.) have an HSS light that fires the multiple pulses of light as the curtains are closing.

And in regard to color, how much to be seen is going to be negligible. In the shots I used, it was an ungelled strobe. In order to get white balance correct, I should have used a CTO gel, but all I was demonstrating was HSS. In midday sun, where HSS is most utilized, gels are not likely to be used because the color temp of the flash is similar to the ambient color temp. 

I've come to equate this thread similarly to the way I treat my patients (I'm a student nurse). Understanding the anatomy and physiology of patients (equivalent to the technical specifications of flash is important), however _how_ useful remains to be seen. Ask a veteran nurse of 20 years how myofibrils work in the muscle - in most cases, they won't remember. Because I ran through my thread similarly about 2-3 weeks ago, what I learned is that a.) I _can_ combat motion and the HSS barrier with my current setup and b.) how do I utilize it and c.) how does it affect my images. 

I used to own a $20 RF trigger off of ebay. While it didn't work consistently, when it did work, it was MUCH simpler to shoot with. I rarely focused on all the other nuances of HSS and shadows, etc. Granted, I'm learning more, my new system allows me to do much more. Finding what works for you, and how to best utilize it will be more valuable than remembering information that won't tell you how to set up your shot.


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## lennon33x (Jan 5, 2014)

Here's an example of why I'll end up using HSS more often than normal.
85mm ISO 100 f/1.4 1/500




Because I was in my garage, I wanted to have the least amount of background in focus as possible. I needed my strobes with a soft box and grid because of the "look" I was going for and there was just too much ambient light being allowed by the wide aperture. Even at 1/400, there was still significant background showing up. Once my modifiers were in place, I adjusted the SS accordingly. I was able to do this not because I know everything there is to know about the way my strobe works, but because I know how to utilize my system.


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## beachrat (Jan 5, 2014)

reavesce said:


> Here's an example of why I'll end up using HSS more often than normal.
> 85mm ISO 100 f/1.4 1/500
> 
> 
> ...



I'm a bit confused why you took that shot at f1.4? There's nothing noticable to render out of focus that I can see,in fact it's black.
Did you post the wrong pic maybe?


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## lennon33x (Jan 5, 2014)

No, I did it on purpose. In test shots, I stopped down, but it a.) gave me a greater depth of field, and b.) changed the light on my subject.


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## lennon33x (Jan 5, 2014)

beachrat said:


> reavesce said:
> 
> 
> > Here's an example of why I'll end up using HSS more often than normal.
> ...



Let me ask you this then:

Had I shot this image at full power, with a soft box and grid, ISO 400, f/9 1/250, would it have been "right?"


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## beachrat (Jan 5, 2014)

reavesce said:


> No, I did it on purpose. In test shots, I stopped down, but it a.) gave me a greater depth of field, and b.) changed the light on my subject.



Interesting.
I would have done it differently,but that's what makes the world go 'round.

_
"Let me ask you this then:

Had I shot this image at full power, with a soft box and grid, ISO 400, f/9 1/250, would it have been "right?""_

I definitely wasn't telling you what to do,just asking why.
"Right" will always be subjective I guess.
I probably would have started at around f5.6 and iso 200.


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## hombredelmar (Apr 3, 2014)

syndicatedshannon said:


> Thanks again for the help. I just wanted to report back a little bit of research on high-speed flash operation.
> 
> *Variable-duration vs. Variable-voltage
> *These two types of flash can typically be distinguished as follows:
> ...



That is deep!


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