Here are some more examples of varying degree. With Superpan 200 and a red filter and slide film. There are many rolls that have come off this camera that are outstanding.
now I see it
I would say there is a light leak within the lens itself since it does not occur with any other lenses (it would if it was with the body). Perhaps a loose rear gasket or a broken seal? The constant curve of the light seems to indicate it is before at least one layer of glass, whereas other light leaks I have seen are more straight.
Could it be a failing shutter?
I think the lens is at fault. Best to try it on another camera in bright lighting and see.
creasing of the film when loading it onto ss reels also gives somewhat of a similar look. But it's very obvious on the film itself.
Those look precisely as my negatives do if I scan them the moment they're dry. My rather lame scanner doesn't hold the ends flat unless they completely fill the negative holder, end to end. Are these marks ONLY at the ends of each strip - because that's where they appear on mine. No such issues if/when they've been sleeved/flattened overnight.