I’ve actually just designed a bracket for a reflected laser sprocket hole sensor to retrofit onto my build - I’ve had pretty good results with my setup so far with my angled “through the film” laser/detector but I’ve noticed some stability/reliability issues with some of my films and I’m planning to test a reflective design. This bracket would hold the laser on the left and the sensor on the right with the convergence point right in the film plane as it passes out of the gate. The next iteration of this design will likely have another guide path for the film since it floats in free space at the moment at the point of “detection”.
@jankaiser I did indeed use a pinhole to improve the effective resolution of the sensor - I’m planning on continuing to do that with this new build since it did seem to make a significant improvement in the result. Ideally I’d replace it with a condensing optic, but it starts to add more complexity.
You might have some tuning to do with the strength of the laser and the sensitivity of the sensor - mine definitely have a sweet spot that I’m not looking forward to having to “rediscover” with a different design 