HSS (High-Speed Sync) and image quality

[lennon33x]

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?

 

[EIngerson]

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.

 

[syndicatedshannon]

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.

 

[lennon33x]

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

 

[pixmedic]

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.

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?

 

[Mach0]

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.

 

[syndicatedshannon]

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!

 

[pixmedic]

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.

 

[Mach0]

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!

 

[Mach0]

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.

 

[lennon33x]

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.

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.

 

[Derrel]

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!

 

[Mach0]

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.

 

[lennon33x]

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.

 

[syndicatedshannon]

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.