Faking strobes

[I Bloom]

So I'm doing a scene next month where a character is taking snapshots, and the director wants the flashes to appear in the image.

It shouldn't be too hard to do this in Shake, since it only occupies one frame a few times but I'm kind of into the idea of doing it in camera for many reasons.

Has anyone had any luck syncing the RED to strobes. Is there a special unit that will ramp up for a little longer than one frame and avoid rolling shutter artifacts?

IBloom

 

[hunterrichards]

This is just a complete guess, but I beileve you can set the "shutter" on the flash. Maybe putting at the same shutter as what your shooting at will work?

 

[David Battistella]

I would say that the light needs to expose for as long as the shutter does plus the "extra" time needed to have the sensor do a full scan.

I think "raging bull" has a great example of flash duration. Maybe you could use those old site "flash pots" to do the strobe, or select a strobe the looks un naturally long to the eye but will be perfect with RED.

The failsafe is to add them all in post and use the sound track to sync them.

David

 

[Anders Yarbrough]

From what I've seen and heard (from talking to prop masters, etc.). You need to get the old (one time use) GE flashbulbs off ebay or a garage sale, or maybe someone still makes them. The one time use bulbs have a longer burn time that is more easily captured by the camera than reusable flashes.

http://www.pacificrimcamera.com/catalog/ej62.htm
http://portland.craigslist.org/wsc/clt/823871364.html

Your effects/props man should be able to rig a paddle up with multiple sockets and switches to fire off the bulbs with a 9v battery.

Good luck.

 

[Erik Bien]

Flashbulbs are still available through Cress Photo.

 

[Michael Lindsay]

is the flash source in shot?

 

[conrad gaunt]

I've done a lot of stuff with post strobing. I usually write a tool to process such effects onto a sequence of images, sometimes just to stress temporal codecs.. but remember that strobing can trigger fits in some people. I think in the UK (I could be wrong) strobing above 5fps is not allowed in childrens programs, or for very long...

 

[C.H.Haskell]

I am about to do a commercial with lots of strobing at one point, plan to use the vintage bulbs, anyone use these with success given they have a longer flash? Any reports of rolling shutter artifacts when using them? I really dont want to spend time in post but I will if its the only way to get strobing.

thanks.

 

[C.H.Haskell]

I am about to do a commercial with lots of strobing at one point, plan to use the vintage bulbs, anyone use these with success given they have a longer flash? Any reports of rolling shutter artifacts when using them? I really dont want to spend time in post but I will if its the only way to get strobing.

thanks.

Anyone?

 

[Evin Grant]

I've used studio strobes with some success. You need to fire them at full power and you'll get about 50% full frame.

Here's an example, about 1/2 way through.
http://www.evingrantdp.com/Koi.html

 

[C.H.Haskell]

Thanks Evin...looks great man, well done. By 50% you mean brightness? Cause I dont notice it clipping in half like I usually do. What if I am over cranking some...will this creat a longer or fuller strobe? Thanks again man.

 

[I Bloom]

I just used the vintage bulbs with success, only problem is they only fire once so you need multiple rigs if you use them twice in the same shot. Otherwise you get about 1.5 frames per strobe.

Also the FF-33 last a full second, but they are 50 bucks a pop. literally.

IBloom

 

[C.H.Haskell]

So the FF-33 las t full second mean 24 frames and the other only 1.5 frames? I want a good flash...but 50 bucks! Really need to rehearse this shot! Thanks Ion.