Donald Qualls
Subscriber
Note: not that this looks like very typical x-ray damage. It's too localized and too neatly aligned with the edges of the film to my taste.
Not to mention it doesn't have the density level I've seen in past posted examples of X-ray damage, nor does the fogging cross the rebate. I'm pretty convinced this is (somehow) happening in camera, but I don't have an explanation how it can happen in multiple cameras with different shutter travel direction.