Thanks for the details, Zach! Looks like a good working alternative, and one that can be improved when new cameras become available.
-JH Jason Halprin jihalp...@gmail.com On Wed, Oct 28, 2015 at 10:19 AM, Zach Poff <z...@zachpoff.com> wrote: > I have much to say about film-to-video transfer using frame-by-frame > techniques, but I've been putting off making a page about it on my site, > due to the enormity of the task and my limited time. I run the film > facilities at Cooper Union Art School, where we teach 16mm and sometimes > Super8. I spent a few years slowly building our current system, which does > sharp 1080p transfers of 16mm reversal, prints, or negatives. My solution > is based on parts we had available, some purchases from eBay and elsewhere, > and my own history using the MAX visual programming environment to make my > artwork. > > First, a quick note: Mirrorless cameras DO have shutters even though they > lack mirrors, so a mirrorless cam will die on a JK just like an SLR. > (Though some of the very newest ones have an all-electronic shutter mode, > often with reduced dynamic range.) > > I can't explain every detail of our system here, but this is the general > idea: > > A (mirrorless) Panasonic GH2 camera body with macro bellows + enlarger > lens is focused on the filed-out gate of an Eiki slotload projector. The > projector has been modified: Shutter removed, sound-reader removed from > film path, motor replaced with gear-head DC one, lamp replaced with RGB > LED, power-supply replaced... > > An Arduino microcontroller inside the projector communicates with a nearby > computer via USB. The Arduino controls the motor speed and direction, > senses when the mechanism has advanced each film frame, and dims the LEDs > (via a high-speed PWM controller). When a frame is stationary in the gate, > the LEDs are on, but when film is in transit they turn off. So when the > motor is running the LEDs blink once per frame. (This detail is crucial.) > > The computer is running a custom app (created with MAX) that communicates > with the Arduino and manages a live video feed from the camera. The camera, > like many recent mirrorless cams, outputs a 1080p signal via HDMI which we > feed through a Matrox capture box and display on the computer screen for > focus and framing. The software is also checking the brightness of the > sprocket hole (revealed by the filed-out gate). > > When you begin recording, the projector motor turns on and the software > captures the first illuminated video frame to disk then waits for the next > one.... It's a slow process (about 4fps) but way faster than the JK (<1fps) > and doesn't kill any DSLR shutters. After the capture is done, all the > uncompressed frames are rendered out to your choice of codec (we use Prores > 422) with optional image processing like curves, color-inversion, > image-flipping, pillar-boxing, etc. > > The filed-out gate can cover Super16 or the soundtrack of prints, which we > can translate to sound via AEO-Light > <http://sourceforge.net/projects/aeolight/>. > > The drawbacks are: > > It's home-made, so not easy to replicate with common materials. It's slow. > It requires a specific camera shutter speed to eliminate PWM flicker. The > GH2 is not the ideal camera (limited dynamic range makes reversal transfers > too contrasty, needed firmware hacking to fix HDMI problems, needs to be > recording to SD card to enable high-quality HDMI outs, even though we don't > use the SD card recordings!) More recent cameras like the GH3 would be > fine. The software is somewhat fragile because MAX is inefficient. (We use > a fast SSD for captures but if you try to multitask during capture you'll > get dropped frames.) > > Some pictures are here: > > http://www.zachpoff.com/site2/wp-content/uploads/1-HD-Telecine-wide.jpg > > > http://www.zachpoff.com/site2/wp-content/uploads/2-HD-Telecine-Wide-lamp.jpg > > > http://www.zachpoff.com/site2/wp-content/uploads/3-HD-Telecine-lamp-close-up.jpg > > > http://www.zachpoff.com/site2/wp-content/uploads/4-HD-Telecine-internals.jpg > > > http://www.zachpoff.com/site2/wp-content/uploads/5-HD-Telecine-pressure-plate.jpg > > > http://www.zachpoff.com/site2/wp-content/uploads/6-Cooper-HD-Telecine-screenshot.jpg > > > http://www.zachpoff.com/site2/wp-content/uploads/7-Cooper-HD-Telecine-sample-frame.jpg*(that's > a frame from reversal. Color neg looks awesome too.)* > > -Zach Poff > > > > _______________________________________________ > FrameWorks mailing list > FrameWorks@jonasmekasfilms.com > https://mailman-mail5.webfaction.com/listinfo/frameworks > >
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