Has anyone tried this - sync beyond max sync speed

[rpcrowe]

I just watched a YouTube video that seems to say you can shoot with a higher shutter speed than the maximum camera sync speed, without using HSS.

https://www.youtube.com/watch?v=MUwfwFYl2MY

I will try this tomorrow with my Canon gear. But, I wonder if anyone has tried this system?

[dje]

I just watched a YouTube video that seems to say you can shoot with a higher shutter speed than the maximum camera sync speed, without using HSS.

https://www.youtube.com/watch?v=MUwfwFYl2MY

I will try this tomorrow with my Canon gear. But, I wonder if anyone has tried this system?

Hi Richard

I'm not sure what this guy is doing, his explanation is not very good. My guess is that he is just using High Speed Sync. I can't see how you can do it any other way. I'll be interested to see what you find.

Dave

[george013]

Hi Richard

I'm not sure what this guy is doing, his explanation is not very good. My guess is that he is just using High Speed Sync. I can't see how you can do it any other way. I'll be interested to see what you find.

Dave

He doesn't explain anything.
There are some camera's that has a different curtain behaviour. One of them was the D70. It did have a sync speed but you could get over it.

George

[Steaphany]

I'm suspecting the technique is based on a strobe being fired prior to the shutter and illuminating the scene long enough for the shutter to open and close. The problem with the video is he fails to specify what equipment he is actually using and there is no way to assure that this technique will apply to every camera and strobe combination. Another factor is the date of the video, 2012, and we have all seen how quickly technology evolves, what he used to pull off this trick may not be available today.

A key reason of the sync shutter speed limit is the focal plane shutter which is a standard in modern SLRs.

If you want a real method to get around the sync shutter speed limit you can move to a camera lens system that uses an in-the lens leaf shutter or you can find a continuous video light to illuminate the scene while you snap the photo. Watch if you choose a LED video light, the electronics will often pulse the LEDs. This will be of a frequency high enough to not be an issue for the video camera, but if you are shooting at 1/1000th or shorter, you may capture a moment between LED flashes.

[Shadowman]

The external flash intensity and in-camera flash setting he used was easy to set, but he didn't show how the shutter speed was changed.

[inkista]

I'm wondering if he was confused and thinking FP meant "full power" (for the Canonites: other brands calls HSS "focal plane" or FP flash), or he was just tail-syncing.

Tail-syncing (aka Supersync, Hypersync, etc.) works if you have the right light/trigger combination but sometimes requires the ability to adjust the sync timing, and you'll still get a bit of a gradient. My YN-622C triggers can do this, but weirdly only with my 580EXII, and NOT with my YN-560. No freaking clue why. (And it's definitely not using HSS--I'm connecting the trigger via PC sync port) Tail syncing is more commonly used, as I understand it, with studio strobes.

Basically, flash "power" is a misnomer. The power of the flash burst is actually set by its duration. The higher the power, the longer the duration of the burst. By the time you get to full power on a speedlight, the duration of the burst may actually be longer than your shutter speed--if your shutter speed is high. Generally, the flash has to be at full power, and the shutter speed above 1/1000s.

When a flash burst dumps light, most of the light comes out at the beginning of the burst, but then tails off to be more even. If the camera syncs the shutter a little late, it misses the bright even burst, but can expose during the "tail" to get more even illumination across the frame. But this is a game of diminishing returns, and precise timing, so it's often not worth it. It can waste more light/power from the flash than HSS does.

The other way to get higher sync speeds--and Richard this might work with your new SX50, if it's like the Powershot Gs--is if the camera has a leaf shutter. They just sort of naturally sync with manual flash at higher speeds. My G9 easily syncs up to 1/1250s and my X100T does up to 1/1000s with simple manual radio triggers (Yongnuo RF-602). No special anything required.

[george013]

I'm wondering if he was confused and thinking FP meant "full power" (for the Canonites: other brands calls HSS "focal plane" or FP flash), or he was just tail-syncing.

Tail-syncing (aka Supersync, Hypersync, etc.) works if you have the right light/trigger combination but sometimes requires the ability to adjust the sync timing, and you'll still get a bit of a gradient. My YN-622C triggers can do this, but weirdly only with my 580EXII, and NOT with my YN-560. No freaking clue why. (And it's definitely not using HSS--I'm connecting the trigger via PC sync port) Tail syncing is more commonly used, as I understand it, with studio strobes.

Basically, flash "power" is a misnomer. The power of the flash burst is actually set by its duration. The higher the power, the longer the duration of the burst. By the time you get to full power on a speedlight, the duration of the burst may actually be longer than your shutter speed--if your shutter speed is high. Generally, the flash has to be at full power, and the shutter speed above 1/1000s.

When a flash burst dumps light, most of the light comes out at the beginning of the burst, but then tails off to be more even. If the camera syncs the shutter a little late, it misses the bright even burst, but can expose during the "tail" to get more even illumination across the frame. But this is a game of diminishing returns, and precise timing, so it's often not worth it. It can waste more light/power from the flash than HSS does.

The other way to get higher sync speeds--and Richard this might work with your new SX50, if it's like the Powershot Gs--is if the camera has a leaf shutter. They just sort of naturally sync with manual flash at higher speeds. My G9 easily syncs up to 1/1250s and my X100T does up to 1/1000s with simple manual radio triggers (Yongnuo RF-602). No special anything required.

I wondered why, to proof he can pass the flash sync, he is using a remote flash and not just simple the flash on the camera. I think he is fooling us.


George

[inkista]

I wondered why, to proof he can pass the flash sync, he is using a remote flash and not just simple the flash on the camera. I think he is fooling us.

No, this is a real thing. And if the flash is on-camera, the he can use HSS. Most radio triggers can't. So, remote flash is more proof of what he's doing. He's just REALLY bad at explaining what he's doing. But if you need better demonstrations:

Pocketwizard's page on Hypersync.

And their wiki page on how it works.

And here's someone posting their testing on the YN-622C supersync feature.

And flash havoc's article on Phottix's ODS timing adjustment.

It's a real thing.

[dje]

Kathy, thanks for enlightening me on Hypersync, those articles are very useful. I don't have an external flash trigger so I was unfamiliar with this technique.

The key to it is changing the synchronization of the flash so that it starts just as the first curtain is opening rather than just after the first curtain has closed. This is similar to HSS. In many cases, the flash duration on full power should be long enough to fully expose the frame at higher shutter speeds.

Dave

PS : Just noticed a similar comment from Steaphany above.

[george013]

He is using 2 speedlights.
I don't see any other solution then a longer flash exposure. The longest is about 1/1000s, the speed of the curtains stay 1/250, or about that. To cover the whole sensor the flash duration should be 1/250.
I don't know why a speedlight can't do HSS when off camera.
And I still don't know what camera he is using. Yes, a Nikon but which one.
George

[dje]

He is using 2 speedlights.
I don't see any other solution then a longer flash exposure. The longest is about 1/1000s, the speed of the curtains stay 1/250, or about that. To cover the whole sensor the flash duration should be 1/250.

In this case, ideally the flash duration needs to be longer than 1/250 plus 1/1000 or about 5 ms.

Here is a measurement I did recently of my SB500 on full power and mounted on the hot shoe. The duration happens to be 5 ms. If the flash were to be used via an external trigger, it is quite possible that a flash duration longer than 5 ms would be possible.

The decay in amplitude would cause some variation in exposure across the frame.

Dave

[george013]

In this case, ideally the flash duration needs to be longer than 1/250 plus 1/1000 or about 5 ms.

Here is a measurement I did recently of my SB500 on full power and mounted on the hot shoe. The duration happens to be 5 ms. If the flash were to be used via an external trigger, it is quite possible that a flash duration longer than 5 ms would be possible.

The decay in amplitude would cause some variation in exposure across the frame.

Dave

I remember that diagram and that thread.
I tried to find some specs of the speedlights. For the exposure he uses the SB900, as commander the SB600.
Flash duration of the SB900 concerning Nkon is 1/880, 1.14ms. It seems they use a t0.5 measurement. Using t0.1 the flash duration is 1/230, 4.35ms.
But the amount of light that's used for exposure is getting very small with high speed. If 1/x is the sync time and 1/y the shutterspeed, than the effective amount of flashlight being used is x/y. In his example he is using 1/5000 and let the sync time be 1/250, than he is using a 1/20 part of the available flash light.
When the camera uses a normal curtain shutter.
http://speedlights.net/2010/12/21/ni...dlight-review/
George

[dje]

I remember that diagram and that thread.
I tried to find some specs of the speedlights. For the exposure he uses the SB900, as commander the SB600.
Flash duration of the SB900 concerning Nkon is 1/880, 1.14ms. It seems they use a t0.5 measurement. Using t0.1 the flash duration is 1/230, 4.35ms.
But the amount of light that's used for exposure is getting very small with high speed. If 1/x is the sync time and 1/y the shutterspeed, than the effective amount of flashlight being used is x/y. In his example he is using 1/5000 and let the sync time be 1/250, than he is using a 1/20 part of the available flash light.
When the camera uses a normal curtain shutter.
http://speedlights.net/2010/12/21/ni...dlight-review/
George

George I don't place much importance on the one line Speedlight flash duration spec (the SB500 is 1/1100s at full power). The measurements I did indicate that at full power, the flash duration is anywhere between 1ms and 5ms depending on shutter speed. The decay time doesn't seem to change, the pulse is just truncated after a certain time.

Yes the exposure is using a small amount of the available light from the flash at fast shutter speeds but this just determines how close the flash needs to be to the subject, in conjunction with aperture and ISO, for proper exposure. In other words, with HSS, the Guide Number drops as shutter speed increases.

Dave

[Manfred M]

The video is certainly not clear as to what is happening here, but at a high level (with a bit of help from the PocketWizard wriite up and Dave's graphs), I can see what is happening.

By shooting at full power the flash outputs ~ 1ms pulse of light, so as long as the shutter speed is fast enough (greater than 1/1000th s or so), for all intents and purposes we have a short burst of "continuous" light, from the sensor's point of view. In fact, the faster the shutter speed, the light less drop off will come into play (the front end of the trace that Dave has shown).

The only real "issue" is that the the light has to fire just as the first shutter blade starts to move. I suspect that is why the flash has to be in manual mode to ensure that the flash and camera software don't get confused and try to do something that is outside of the program parameters. PocketWizard does warn that a gradient can appear, and of course this would come about as a result of the flash drop off.

I wonder how this technique would work with studio flash as there is sometimes a longer delay to full power output.

Thanks for posting Richard; this certainly provides something else to play with in our spare time. Different triggering modes (direct, master/slave and RF triggers) could all give slightly different results, depending on any delays in triggering the remote flash by the additional components in the chain.

[dje]

The only real "issue" is that the the light has to fire just as the first shutter blade starts to move.

Yes I think that is the key to using high shutter speeds (ie ones above the sync speed). This is what happens with HSS.

The thing that puzzles me with the video is how is this achieved. He is using optical triggering of the remote flash so there are no synchronization tricks available from Pocket Wizards or the like. I'm still inclined to think that at least the master flash on the hot shoe is operating in HSS mode which would cause earlier triggering of the remote flash. The remote flash is probably operating in normal mode.

Unfortunately I don't have enough gear to test it ! Perhaps I should do something about that.

Dave

[george013]

George I don't place much importance on the one line Speedlight flash duration spec (the SB500 is 1/1100s at full power). The measurements I did indicate that at full power, the flash duration is anywhere between 1ms and 5ms depending on shutter speed. The decay time doesn't seem to change, the pulse is just truncated after a certain time.

Yes the exposure is using a small amount of the available light from the flash at fast shutter speeds but this just determines how close the flash needs to be to the subject, in conjunction with aperture and ISO, for proper exposure. In other words, with HSS, the Guide Number drops as shutter speed increases.

Dave

Dave,
That thread you're referencing to was about the 2 different sync-speeds. You where using iTTL but not with the maximal setting.
This guy is using manual and max. power.
Flash duration is calculated in 2 ways: T0.1 where the flash intensity is minimal 10% of the max intensity and T0.5 where the flash intensity is minimal 50% of the max, intensity.
It's not only that the flash duration must have a minimal time of 1/250, the curtain speed, also the moment of the flash must be changed in a way. Under normal conditions with a shutterspeed of 1/5000 the flash will start when the 2 curtain has closed nearly. I think he needs rear curtain flash, flash starts just before the 2nd curtain closes. but I didn't hear hem saying.

That are my thoughts.

George

[dje]

Dave,
That thread you're referencing to was about the 2 different sync-speeds. You where using iTTL but not with the maximal setting.
This guy is using manual and max. power.
Flash duration is calculated in 2 ways: T0.1 where the flash intensity is minimal 10% of the max intensity and T0.5 where the flash intensity is minimal 50% of the max, intensity.
It's not only that the flash duration must have a minimal time of 1/250, the curtain speed, also the moment of the flash must be changed in a way. Under normal conditions with a shutterspeed of 1/5000 the flash will start when the 2 curtain has closed nearly. I think he needs rear curtain flash, flash starts just before the 2nd curtain closes. but I didn't hear hem saying.

That are my thoughts.

George

George the tests I did were with flash power set manually in the camera, not using iTTL. I did three sets of tests with full power, half power and one quarter power although I only reported the half power measurements. The example quoted above is a full power one for a shutter speed of 1/60s.

The SB500 I have is a fairly basic unit and has no settings available on the flash itself. Everything has to be set from the camera. Higher end units do have settings on the flash and this may open up extra options.

I'm not sure I understand your last comments but as far as I'm concerned, with HSS, the flash duration must extend from the start of the first curtain movement until the end of the second curtain movement.

Dave

[pnodrog]

Dave,
I think he needs rear curtain flash, flash starts just before the 2nd curtain closes. but I didn't hear hem saying.

That are my thoughts.

George

An interesting idea but I would assume any camera with HSS sync capabilities would automatically switch to HSS sync as soon as the shutter speed exceeded the maximum for X sync. Certainly if rear curtain sync is available at high shutter speeds the flash should be triggered before the second curtain starts moving and there is a chance that with a long flash duration and at high shutter speeds some sort of flash synchronization would occur.

However I agree with Dave that the on camera flash is most likely operating in HSS mode and will start firing before/as the first curtain starts to move and the second slave flash is triggered at that time in non HSS mode. The photographer then cross's his fingers and toes and hopes that the duration of the second flash at full power is long enough to produce a relatively even exposure.

I recommend you take out a large insurance policy if you are going to get paid heaps of money to shoot an important wedding and then rely on using this technique.

[george013]

George the tests I did were with flash power set manually in the camera, not using iTTL. I did three sets of tests with full power, half power and one quarter power although I only reported the half power measurements. The example quoted above is a full power one for a shutter speed of 1/60s.

The SB500 I have is a fairly basic unit and has no settings available on the flash itself. Everything has to be set from the camera. Higher end units do have settings on the flash and this may open up extra options.

I'm not sure I understand your last comments but as far as I'm concerned, with HSS, the flash duration must extend from the start of the first curtain movement until the end of the second curtain movement.

Dave

From your earlier post here. I just can't explain why the flash duration is depending on the shutterspeed. If it's set to manual, it shouldn't change.

The measurements I did indicate that at full power, the flash duration is anywhere between 1ms and 5ms depending on shutter speed.

What I remember of HSS, is that the flash starts just before the first curtain opens and ends when secund curtain is closed. And the flash is stroboscopic. But in this video no HSS was used.

George

[pnodrog]

HSS strob frequency is I understand about 50 khz So neither our vision nor a video will be able to determine if it was used or not.