Stupid question...

[bella1morgan2]

Can video light be used as high speed sync?

 

[D-B-J]

No. Unless it's some incredibly high output light, the power won't be strong enough for high speed sync. What type of image are you trying to achieve?


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[WayneF]

Can video light be used as high speed sync?

Yes, sure. I may misunderstand the question, but video lights (assuming that means lights suitable for movies) are already necessarily continuous lights. Like sunshine or incandescent lights are continuous light, always on. At least from the shutters perspective, the light is on before it opens, and still on when it closes. So there is no sync issue with continuous light, it is simply always on (as far as the shutter knows).

HSS flash simply tries to mimic continuous light, by flashing continually for a longer time (for the duration of the shutter curtains travel time), to also be on before the shutter opens, and still on when it closes. This bypasses the sync problems that focal plane shutters see with regular "instantaneous" flash (speedlight flash). This is a pretty big deal for a speedlight to be able to do, but continuous lights are already... well, continuous light.

HSS is not at all high speed flash, but instead the opposite - it is merely a real slow light, always on (continuous has no motion stopping capability, same as sunlight has none, but speedlights do). All HSS has is the shutter speed, but speedlights are often much faster than the shutter speed.

The shutter has no sync issues with continuous light, use any shutter speed you please.

 

[Designer]

There you go. Two different answers.

Pick the one you like best and go for it.

 

[bella1morgan2]

No. Unless it's some incredibly high output light, the power won't be strong enough for high speed sync. What type of image are you trying to achieve?


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Do you happen to know what the light output of the HSS is?

 

[Derrel]

Can video light be used as high speed sync?

It will not have a lot of effect as fill light or as a main light source at "high speed" unless the light is very powerful and/or the lens aperture used is pretty wide. Of course, you might have some very bright video lighting setup, or might be using it from a close light to subject distance, and it might provide what you need. There are some variables that were not listed on the original post, which might affect how well the video lights will work for your general uses.

 

[tirediron]

HSS, or "High Speed Sync" is not a measurement of light, rather it's a mode where your camera and speedlight can produce flash exposures using shutter speeds significantly above that of which it is normally capable.

 

[WayneF]

Flash units capable of HSS mode often run about 20% of maximum power in HSS mode, or about -2.3 EV, more or less. Lower fill flash level in fully powered speedlights might be sufficient up to 10 or 12 feet?
More about HSS at Auto FP and HSS - What is it

But if "video lights" means continuous light like any movie camera requires, then there is absolutely no concept of HSS.. Continuous light is already continuous, and ANY shutter speed will work, without any sync issues. There is no concept of sync for continuous light. That is how HSS works, speedlights become pseudo continuous light in HSS mode.

Fast shutter speeds do tremendously limit the continuous light through the fast shutter speed (like sunshine does), but opening the aperture compensates, stop for stop. One feature of continuous light is that Equivalent Exposures work.

Since you keep asking, do you mean something else by "video lights"?

 

[unpopular]

Continuous lamps do not need sync, as been mentioned before - because they're always on. Xeon strobes require to be synced so that the shutter is open during discharge.

Typically speeds faster than 1/250 sync is not possible on modern curtain shutters. HSS is provided to overcome this limitation.

The lamps used in video and cinema must always be lit in order to capture continuous movement. Xeon strobes, while very efficient can only provide one discharge every refresh cycle - the time the circuit requires to provide enough energy to discharge the tube. This can range from 1/15s to several seconds depending on design and power - but not the 1/24s minimum needed for cinema, let alone the 1/60s or shorter for modern cinema practices. Even if the strobe could discharge fast enough to keep up, synchronization would be impossible and their would be a constant flicker on set (along with many other technical issues, and this is assuming that the shutter isn't rolling).

There are, of course, very high output LED panels, which have been very beneficial in very slow-motion capture for film and video since LED panels emit far less heat watt-per-watt than the previously available options. However, these panels would be massive (and I am actually having trouble finding any, though, I know that they exist).

They do make very high output LED modules. An 4x4 array of 500W LED modules for street lamps would illuminate *anything* at any practical shutter speed provided you're working at a close distance. Of course, you'd have to somehow power the array, which would require an 8kw DC supply at 60V with PMW control for dimming, and you'd need to provide adequate [active] cooling.

It'd be epic, though, probably not very practical. While not as cool, a 4-6K HMI would probably work just fine.

Though, if freezing motion is what you're after (and I am guessing it probably is), then there are some key aspects to strobe photography that you need to understand first. For this kind of photography, a high output flash will always be a better choice than continuous since exposure occurs over the duration of discharge, which is shorter than the maximum sync speed.

Shutter speed does not determine strobe exposure, but rather discharge power and aperture.

 

[WayneF]

Typically speeds lower Higher than 1/250 sync is not possible on typical, modern curtain shutters. HSS is provided to overcome this limitation.

 

[unpopular]

fixed.