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.
Attachment 37465 Attachment 37466
Anybody with any ideas ?
Neither foam seals nor pressure plate.
Thanks Mark. I'm unsure what to test for if the lens is faulty.
I have replaced all foam seals surrounding the door at least 6 months ago. They are as good as new.
I inspected the pressure plate and it appears to be working OK. Its springs compress about 1.5mm when closing the lid. There appears to be even pressure along the two outer rails. Placing ink on pressure plate and closing lid transfers ink to a piece of paper which wasn't quite wide enough so I moved it across and closed lid a 2nd time.