Having now stared at my Pi monitor for several days it occurred to me that it may be possible to use a monitor for registration. My poor quality image shows a device that fits onto the front of a monitor and uses an optical sensor to detect transition from white to black. The sensor position can be varied and positioned in the best place for damaged sprocket holes. I am assuming that film with a clear base will still produce a shadow line at the sprocket hole which can be detected.
Nice hack. I hadn’t thought of that one. Any luck?
Cheers, Just getting components, should have a trial ready over the weekend