u/Kippenoma

I've been super curious about this but I don't know where to ask, haha

My friend seems to believe that even after advancing the film is rewinding itself and showing this 'beginning scratch'

She sent a full cartridge in for developing and the lab sent it back because it was not yet exposed according to them, because they could see this 'beginning scratch'

Is this really present on all rolls of film? Is it possible the camera is doing this at all? It seems really unlikely for the cartridge to rewind itself, considering it generally only wants to move one way

So my friend is trying to use a Canon Auto Zoom 518 SV Super 8 for her new short film project. However, the first roll of Vision 3 500T she sent in got sent back, the lab saying the start mark was still visible and the film had not at all advanced. So we put a roll in and yes, it seemed like the roll was not advancing, even thought when fired empty, everything seemed to work fine.

I then tested rotating the advance wheel in the film by hand and it took a good few turns before I felt tension and the film started advancing.

I tested it a few times in camera, marking the spot we left off and sometimes it worked, sometimes it didn't. Sometimes the film bulged a bit, sometimes it didn't.

What's likely going on here? I heard there are QC issues with the films, and the camera seems fine... But it's really hard to say.