Hi all. I feel the 120 film back needs a complete redesign. It consistently leaks light from the lid and the film cannot travel through either as it is designed now. It gets hung up from right turns.
I have been been going through a lot of effort to seal the lid, and have been reverse rolling film to get it to travel through.
If if anyone is interested in redesigning the back please chime in or let me know. I have some thoughts on how to change the design and make the lid light right, but I have no CAD experience and can’t edit or create STL files.
hello, we redesigned the film back along with many other aspects of the camera. We added a 2nd knob that helps with advancing the film, and retensioning the film. We increased the thickness of the dark slide, and added a "ledge" to it so that it can not be fully removed. I am currently taking some photos to make sure it functions properly. Here is a photo of my film back.
I was following Devin's writeup and had some thoughts regarding the film back. The inserting and removing the film seems very problematic due to the chance that the film may unwind in either of these situations. For another camera I've built - one of Schlem's Terrapin line of pinhole cameras (which is essentially a film back with a pinhole) the camera used a retaining clip for the film which allowed you to insert and remove the film tightly. The retaining clip is essentially 2/3rds of a tube with a flange at the top. You insert the film in the retainer into the camera (which holds the paper snugly in place) and insert an empty retainer and take-up spool into the other side. When you are finished with the film, it will be wound onto the spool inside the retaining clip, and you simply pull the retainer out, film and all. It seems like a reasonable approach to a problem that will exist in any case.
The dual knobs are a good choice - the ability to tension the film without that second knob is really impossible. Secondarily missing the number and being able to go back - really important.