It's still all a bit Heath Robinson – there are definitely areas for refinement/improvement. But it appears to work pretty reliably, and I'm quite pleased with the results despite the primitive optics. The lens is a £4 smartphone 'macro' lens positioned in front of the Pi camera lens which is unscrewed as much as possible.
The machine uses the Pi camera to take a high resolution image (or multiple images) of each frame of a reel of 8mm film. These are saved as a sequence non-lossy compressed PNG files on the SD card. These are then copied to a PC for further processing and assembling as video. Silent of course - sound has to be added later.
The aim is to make good archival copies of some precious home movies, a lot I inherited, and some I took myself. These films date from the 60s to the 80s. I also recently bought a job-lot of commercial home movies from ebay, to help with testing the telecine – the less the precious films are handled the better.
Here's a video I threw together showing it in action: http://youtu.be/xm3jTsKSOtE
I uploaded some of the test films, too. Basically these show the results straight from the telecine with no additional processing other than using mencoder to make a video resized to 1024x768, and uploaded to Youtube. The sprocket holes are shown to demonstrate the Pi based registration/cropping. Instability in the films is in the original prints, if the sprocket holes are steady.
https://www.youtube.com/playlist?list=P ... tuXlku2PGd
Code, some documentation and designs are on Github here: https://github.com/jas8mm/rpitelecine
It's all a bit rough and ready, as this project has evolved from the primordial soup somewhat rather than being designed – and there are probably better ways of doing some things, and my Python coding is very non-optimal, but hey, it's working at the moment!
Some background: A number of years ago I started by attempting to hack my old Eumig Mark 500 projector – adding LED light, DC motor, Point Grey industrial camera. Controlled via an Arduino from a PC. It was slow and cumbersome and my old projector very tired and worn and had a habit of not pulling the film through and damaging the sprocket holes. Things got very complex, and the project stalled...
Since then the Pi arrived, then its camera, but I was put off a bit using it because the camera only operated in auto exposure mode, and it wasn't possible to fix the white balance. Now solved. Also Dave Hughes' excellent Python camera API makes it easy to interface the camera, and OpenCV/Numpy allows easy handling of the resulting images.
Also last year's announcement of the Kinograph project got me rethinking the film transport, and perhaps using 3d printed parts to handle the film, instead of using a hacked projector. And this project was born...
