Telecine converter project
Finally, the telecine unit is ready! After many refinements and iterations the design is completed enough to publish the results - but of course a document needs to be written.
I believe that I have attained to goal of a teleconvertor that has parts that are available 'off-the-shelf' or able to be created without need for a resident engineer! All of the mechanical parts are 3d printable - except for the drive spindles. The electronic components are readily available; there are a variety of lenses suitable for the project - it's all a matter of which compromise that gives the least angst. Though there are many camera types that could be used in this project, I have chosen an 8M camera, running in 5M mode so that I am able to capture 4k grade footage. Yes, the camera does capture lower resolutions, but I am of the opinion that there already are teleconvertors that will do 'low-res' captures which would negate the reason for designing this unit.
Below is a photo of an early prototype of the telecine. Yes it works well - but is slow due to the high resolution rolling shutter camera being used. Capturing 5M images takes a bit of time, roughly 0.5 sec, then moving and aligning each frame into view takes time also. Roughly, capturing 4 frames a minute with 'HDR' captures (i.e. 5 images captured per film frame), and about 10 frames a minute if only a single image per frame of film. I've tried faster times, but with poor results.
At the moment I have had to rely on experiments to ascertain the camera configuration(s) as I have been unable to locate the Sony datasheet on the camera. I am sure that with more information about the camera that better performance could be attained, however, while the camera datasheet and application notes remain elusive then so too does the opportunity for performance improvements.
The software is custom designed to control the telecine unit. All of the image processing is handled by a host PC, while the details of moving the film and illumination are handled by a proprietory control board connecting to the host. At the moment it handles 8mm Standard and Super 8mm formats without modification. The subtle differences between the formats are accommodated in the software. There is no reason perceived as to why the unit couldn't also process 16mm film, or 35mm film - of course with modification. I personally have no reason to develop 16mm or 35mm capability into the unit, but if there is sufficient interest expressed then I may consider putting the time into it!
Processing the 'HDR' frames requires custom software to combine the 5 captured images into a single image that can be used to create the output video file. I have been creating progressive videos at the frame rate of the film (i.e. 16fps for Standard 8mm; 18fps for Super 8mm) using ffmpeg as the encoder. The output video has been displayed without trouble on 4k Smart TV's, as they are able to display the resolution. Older TV's have had trouble handling the video at that resolution and required the 'film' be processed at lower resolution.
I've discovered from this project that the mechanical side of things are just the beginning of the project - there is so much scope for development with the software; for example, dust and scratch removal, image alignment, colour enhancement, sharpness manipulation, etc.
