Sprocket Registration

[matthewepler]

Cross-posting some posts from another thread that are better categorized here as Sprocket Registration. CLICK THEM TO EXPAND.

Film Advancement - moving the film

One thought might be to use a laser/photocell to reflect off the film base at the sprocket location. Triggering in LOSS of refection would give the location of the sprocket hole. Another thought would be to emulate the way the motion correction software works and use a photocell looking through the image to find the frame line. Combining this with the scheme to advance a given distance, the lack of a frame line would not be a problem, but the first time you find one it could correct the posit…

Film Advancement - moving the film

Another option maybe to have a dumbed down sensor somewhere before the primary capture sensor which a.) exists at a known distance before the primary sensor. b.) continually scans the film c.) uses opencv to look for the edge of an exposure frame. When frame is picked up by this sensor and boundaries recognized, code tells it exactly when to trigger the primary scanner function based on the known distance between the two sensors and the known rotation of the motors. Off the top of my head a p…

Film Advancement - moving the film

I like the idea of the reflective cell. Have you tried using one? Wonder what kind of conditions they need to work well. Found these with a quick Google search: Honeywell Sensing and Control Part Number HLC1395-001 [image] Fairchild QRD1114 Reflective Object Sensor [image] Honeywell Sensing and ControlPart Number HOA1405-001 [image] And then there’s the [6 pages of results at Digi-Key][1]. [image] Anyone know what factors I should consider when buying one? Happy to do tests on multiple…

Film Advancement - moving the film

@cmacd I’m not sure I quite understand the second suggestion, though. Could you draw a quick sketch? Thanks!! @throwcomputer Sounds like an interesting approach if I understand it correctly. When you say dumbed down, but also does CV - does that mean a low-res camera, like a webcam? OpenCV can be processor heavy, especially when running in real-time and definitely when done at higher speeds. And you’re right about the frame lines becoming an issue when there are fade-to-black areas, night sce…