I have artifacts outside my 120 film frames. Why?
I have run at least 8 rolls of film through my Mamiya C330 MF camera and under certain conditions (perhaps slower shutter speeds, and or over exposed images) I get artifacts outside the square frame area on the negative.
They are different in appearance, probably unrelated. Artifact 1 is a parallel line along each of the two frame edges parallel with the film edge, darker at the top of each frame. Artifact 2 is almost like halation spilling over the top edge of the frame.
I'm attaching two photos showing these. The 2nd attachment with orange text on it is a close-up of the 1st with the contrast increased to better show artifact 2.
Anybody with any ideas ?