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Back projection using SR2


Dudu Stoz

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Hi,

I am going to shot a car driving scene inside studio using the SR2 and a 16mm back projection.

My question is how can i sincronize the SR2 movement with the 16mm back

projector so i wont se the black area betwwen the frames of the back projection in

the final footage.

 

Thank's in advance for any information, Dudu .

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  • 2 weeks later...

Dear Dudu

 

If you use a 3 blade shutter projector, like a Kodak pageant you won't have to synchronise them. The result will be a flicker-free perfect image regardless of the speed of the camera or projector.

 

Other equipment will require synch motors on both pieces of equipment or complex encoders/readers/slave motor on the projector

 

Regards

 

Bruce McNaughton

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The camera shutter is open for about half the 1/24th of a second cycle. The projector uses about a quarter of a cycle to pull down, and to solve the flicker problem, it interrupts the display of each frame either once or twice (two or three blade shutter). So, if you just shoot the projected image, you'll definitely get something.

 

Sync between them will different for every take, and you can get a bad luck situation where each camera frame catches the projector's pulldown blade and part of two different BG frames. With the mag off the camera, run the projector and run/stop the camera a few times to see what it looks like in the finder. If it's brighter some times and dimmer others, you have a three blade projector with a wide pulldown blade. For actual shooting, turn the camera on and off a few times at the head of each take to get the same brightness of BG each time. Remember that on a mirror shutter camera, what you see in the finder is exactly what you *don't* get on film. So with a three blade projector, you want the finder dim so the film gets the light. The finder gets the projector pulldown, and the film gets one frame of BG per exposed frame. With a two blade symmetrical projector, you want the finder bright, the film and operator see the same thing.

 

Look at the projector, with it empty, inch it thru a few cycles and look with a flashlight to see how many blades it has.

 

 

 

-- J.S.

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