It could be a tiny hole that doesn't leak enough light to be noticeable when shooting successive shots. If there are long periods between shots, the leak would be more noticeable because more light would have been able to leak through.
It could be a tiny hole that doesn't leak enough light to be noticeable when shooting successive shots. If there are long periods between shots, the leak would be more noticeable because more light would have been able to leak through.
Happens on all lenses?
I suspect light leak.
Load a roll of film. Shoot four blank frames (e.g. with lens cap on). Leave camera in the light for a day with lens cap off. Then run thru four more blank frames.
Will show where the light leak is. Often the leak is affecting a frame other than the one in position. See this thread for an example.
In this case, I'm betting on a hole in shutter curtain.