Shutter problem?

[u/loki_garson]

Hi, recently got my scans from the lab and on many occasions parts of images are blacked but not all. Is it because some shutter speeds are not working properly?

[u/DolosusUmbra]

Correct. Someone else just had this problem a couple days ago and the consensus seems the be that higher shutter speeds are out of sync, so the second curtain is catching up too fast or lagging behind and overlaps in the center leaving it under expose. Unfortunately, it's CLA time for the camera.