High Speed Flash Sync with Magic Lantern !

[Nitroman]

Hi guys ...

I've just posted this question on the Magic Lantern Forum too :

http://www.magiclantern.fm/forum/index.php?topic=6124.msg45493#msg45493

Basically, could Magic Lantern be enabled to allow high speed flash sync with outdoor fill flash ?

If the electronic shutter (in Live View Mode) is used instead of the standard focal plane shutter, could ML allow high speed sync with Canon portable guns at larger distances ?

Thoughts please ... and perhaps pass any useful comments on to ML thread too ;D

 

[Drizzt321]

Hi guys ...

I've just posted this question on the Magic Lantern Forum too :

http://www.magiclantern.fm/forum/index.php?topic=6124.msg45493#msg45493

Basically, could Magic Lantern be enabled to allow high speed flash sync with outdoor fill flash ?

If the electronic shutter (in Live View Mode) is used instead of the standard focal plane shutter, could ML allow high speed sync with Canon portable guns at larger distances ?

Thoughts please ... and perhaps pass any useful comments on to ML thread too ;D

I think you don't have a real understanding of what the sync-speed is. It's the the fastest shutter speed at which the entire sensor is being exposed before the 2nd curtain begins to travel across the frame. Since with faster shutter speeds only part of the sensor is exposed at any one time, what high-speed sync does is do a series of lower-power flashes (since a flash is normally a very short duration) so as the different parts of the sensor are exposed, the flash hits all parts of the sensor.

That being said, you do have a point that with an electronic shutter we could, theoretically, sync across just about any shutter speed. I think.

 

[Nitroman]

That's what I thought Drizzt321 ... and if the focal plane shutter isn't being used we can sync at any speed !

Mirror would need to be locked up (or live view used), but i think it might work without compromising flash reach / distance !

 

[ScottyP]

That's what I thought Drizzt321 ... and if the focal plane shutter isn't being used we can sync at any speed !

Mirror would need to be locked up (or live view used), but i think it might work without compromising flash reach / distance !

If your subject was moving so slowly that you could shoot it with the mirror locked up, why would you need a high speed shutter?

 

[Drizzt321]

That's what I thought Drizzt321 ... and if the focal plane shutter isn't being used we can sync at any speed !

Mirror would need to be locked up (or live view used), but i think it might work without compromising flash reach / distance !

If your subject was moving so slowly that you could shoot it with the mirror locked up, why would you need a high speed shutter?

Erm...it's not that the subject is moving so slowly, is that you want to use a high shutter speed with a strobe/speedlite. Traditionally you were limited to the shutter sync speed or use high-speed sync. But high-speed sync generally (at least with standard Canon ETTL speedlites) reduces the power output substantially. If you want full power, you generally need a whole bunch of speedlites together, or some types of studio lighting.

If you remove the physical shutter from the equation, you basically have the entire sensor exposed all at once, then it's however long the electronic 'shutter' is that determines your sync speed. So you can sync at, say, 1/4000s at full flash power. Can be quite helpful to balance back lit subjects with fill flash, but having that fill-flash be at higher power to balance correctly with the back lighting.

 

[TAF]

Seems like this would be fairly straightforward.

With the 5D3, one can take a still while shooting video. I don't believe the shutter curtains move during this (I just tried it, and while watching through the lens saw no movement), so it would seem the camera uses an electronic shutter in that mode of operation.

All that would be required would be to actuate the hot shoe.

And that would be very useful indeed.

 

[Lawliet]

So you can sync at, say, 1/4000s at full flash power. Can be quite helpful to balance back lit subjects with fill flash, but having that fill-flash be at higher power to balance correctly with the back lighting.

Thats why I love leaf shutter lenses - sync at 1/1600s, makes the batteries of a pack last longer while cutting ambient light motion blur...
Just one hair in the soup: speedlights are awfully slow at full power. About 1/350s t0.1, thats why Nikon warns that xsync expanded to 1/320s might lead to reduced flash output. Good news: they're IGBT controlled, at 1/4 power you already get better then 1/2000s t0.1. And then we think of the Bron Move 8)