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Capturing Digital Monitor Image on Celluloid


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For a certain effect, I would like to experiment with shooting a computer (Mac) monitor (playing back sync sound footage shot with DSLR at 24fps) with a Super 8 film camera (which is capable of 24 fps crystal sync and a gate widened to capture 16x9), in effect, transferring digital footage to Super 8 which would then be processed and scanned back to digital.

Anyone have any experience with this? Any recommendations on which film stock (Kodak Vision 3 200T or 500T, perhaps) to use? Any foreseen problems with scan lines or the like? I haven't shot a screen since back in the days of NTSC SD interlaced video which obviously produced scan lines. Should I expect anything similar to that? Advice about setting the refresh rate on the computer? Other issues to look out for?

Thanks!

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The big issue there is that the computer monitor won't be displaying each of the video frames exactly once (or a consistent number of times) and even if it was, the playback won't be synchronised to the camera. This means you're likely to get film frames with two video frames exposed into them. You may also face flicker issues as many modern displays use PWM-controlled backlights.

If I needed to do this I'd rig something up to use a camera with a stop motion mode and go frame by frame. It'll be slow, but with testing and enough screwing around it ought to be possible to make it look OK. That assumes the camera is usably steady in stop motion mode, which I understand some super-8 cameras aren't, particularly.

You may find you need to apply a very odd colour correction on the computer to make it look as you want on film.

Definitely don't expect it to work first time.

P

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Documenting the progress on our legged robot on 16mm, I filmed dozens of engineers in front of their desktop and laptop LCD screens from various brands and in different lighting condition at 24fps, and had no flickering nor banding issue like on a CRT.

The colors shifts can be weird though, depending on the brand of the screen.

 

edit:

when your footage playing on the screen is running at 24 fps  and you're  capturing the footage at 24fps two things can happen:

A: the switch to the next image of your screen footage is  always happening during the closed shutter phase of your film camera - meaning you will  always record a single frame displayed on the screen onto a single frame of film.

B: the next image of your screen switches when your shutter is open on your film camera - you will always record two frames of screen footage onto one frame of film - for fast moving objects you will see the image shift of the two frames.

 

So Phil's method of shooting frame per frame might be the safest one

 

Edited by David Sekanina
correction
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Thanks for the replies - very helpful!

I will be using a refurbished Beaulieu 4008 ZM2 Super 8 camera which by design has a somewhat narrow shutter angle. I don't know the exact angle offhand, but the info I've found says the shutter speed is 1/86th of a sec. at 24 fps. Not sure what it is for single frame (and I do have a cable release, thank goodness), but it's likely about the same. Getting consistent shutter speed while single-framing is unlikely, so I'd probably get flicker regardless going that way. That sort of flicker would not be a problem for me given the effect I'm after.

Then, of course, single-framing also presents a much more labor/time-intensive process, but I'm willing to do it to get the best results. ?

Given the faster shutter speed, should I still expect multiple (2) digital frames on some film frames?

The main thing I'm concerned about is getting scan lines. Given that the digital video is progressive, of course, and given that the monitor refresh rate is 60Hz, should I expect them?

I anticipated the color shift, so I was planning to experiment with filters (good idea?) during my test shoot, though since I'd like to use 200T (rather than 500T) to reduce film grain, I'm concerned about having enough light from the monitor. (Haven't tested it with a spot meter yet.) I guess I could experiment with color grading the digital video prior to filming with Super 8 to compensate for the color shift, right?

Anyone have links to examples of footage shot under similar circumstances, even with 16mm or 35mm film?

Thanks again!

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