Why?

[zou]

So, film folk, why did my roll of film snap when rewinding? Anything I should be checking? Once I've got the remnants out (changing bag should make that safe enough, if the film isn't completely ruined already), I'll check that the 'clutch' on the rewind is working, but anything else?

[gray1720]

I wish I knew. It takes a fair amount of force to actually snap a film. Remind me, is it an auto rewind or hand?

[zou]

Jul 7, 2024 18:57:20 GMT gray1720 said:

I wish I knew. It takes a fair amount of force to actually snap a film. Remind me, is it an auto rewind or hand?

Hand. I don't even think there was that much tension on it, I shot the final frame and the advance wouldn't, so I pushed the wee nubbin and did the rewind. Reckon I've got between half and a third on the spool.

I'm also pondering whether it was a rather old roll or a newer one.

[gray1720]

Nothing to suggest that at any point you might have split a sprocket hole?

TBH I think I'm clutching at straws too.

[spinno]

Jul 7, 2024 19:21:12 GMT zou said:

Jul 7, 2024 18:57:20 GMT gray1720 said:

I wish I knew. It takes a fair amount of force to actually snap a film. Remind me, is it an auto rewind or hand?

Hand. I don't even think there was that much tension on it, I shot the final frame and the advance wouldn't, so I pushed the wee nubbin and did the rewind. Reckon I've got between half and a third on the spool.

I'm also pondering whether it was a rather old roll or a newer one.

happened to me the other week, slightly different circumstances. I'd repaired my P30t and put a reused roll through it, all seemed well, I'd checked the handle going round as I wound forwards, reached the end of the roll and went into reverse. That's as far as I got, the last dreg of the  film just flew (I assume) out of the cassette.
Found an old unexposed film and ran that through and all seems fine (note to self get it developed), so old film seems favourite although in my case it had been through a couple of times .

[zou]

Oh, now there's a thought spinno - I think this is the roll I started in my MG and switched to the K2. So one, it's probably had more light leak/exposure than I initially thought, and 2, having been partially shot/rewound I wonder if maybe the film was partly damaged or curled so as to perhaps not properly align?

[zou]

For reference having shot a few frames the back plate on the MG opened a bit. Hopefully not enough to goose the handful of shots, so I rewound in the dark bag and was sure to leave the leader out enough to get it into the K2. Then shot the approximate number of frames with lens cap on to get the film to about the right place.

[geoffr]

The reason I stopped shooting film was that the tape securing the film to the spool in the film can broke. It was just a one off but all the film I had with me was the same batch and I didn’t have the necessary tools to hand to rewind the broken one, they were 4,000 miles away. Not your problem, but the tape was the weakest link, breaking a 35mm film isn’t easy and the rewind lever surely doesn’t provide sufficient mechanical advantage. I would think that under normal circumstances the lever would bend before the film broke. Is there anything sharp inside the camera that it could have snagged on? Is there any evidence of previous damage to the film?

[zx9]

I can remember my father breaking films in a Fed4, it was a regular occurrence for something to go wrong with that camera. I have seen the odd ripped sprocket when the rewind button has popped back out during rewind but the feeling of something been not right is so obvious especially for someone of your experience that you instantly stop and investigate.
I can't think what happened to not alert you, was it old previously frozen film stock? Are both cameras Pentax 'magic needle' take up and do they both have the same direction of wind / curl? I ask the last part because my Leica M2 puts a reverse curl into the film, there is no way I would attempt to re use one of it's part used films in my Y/C SLRs which load in the conventional way, I could see that going wrong in the initial take up.

Lets just hope that it was a one off.

[Fenris]

This is a weird one. I've only ever had sprocket holes split/tare, never a film totally snap.

Only thing I can think of is perhaps the film was damaged when it was originally wound onto the roll? Something like a crease or fold in the film before it was rolled and that weakened it so when it was used it... snapped.

[donerundlecams]

FWIW, I've switched plenty of films from one camera to another with no problemo.  I have had one or two films that broke and, if memory serves, it was a sprocket tearing part of the film. Although, I did have one time, and I certain that this reason doesn't apply here,  when I was taking snaps in -25C to -30C weather and, I think, the film broke / snapped due the cold weather  .  Luckily, I had a few rolls that were OK ().

Cheers,
Jack