Quote Originally Posted by Bill Burk View Post
I had once taken this to the level of obsession, like a nervous tic, even though I knew film was loaded, I'd cinch the rewind practically every time I had the camera around my neck. I got all these dark crescent moon shaped stress marks in the skies of all my horizontal slides taken with 35mm lens on OM-4. When I stopped that habit the marks were less prevalent though still happened occasionally - I think I reduced the habit but still did it from time to time.
I always liked having the film a little loose in there- the rewind knob would still turn, but if the knob got bumped while I was carrying the camera or something, there would be some rotational play. I had heard that cinching could cause scratches.
It makes sense that the film could get pulled at a sharp angle inside from cinching, especially near the end of the roll, and leave marks. It seems to me that it would have been good for manufacturers to warn about cinching.