I have had this problem since I first got my Hasselblad 501CM: some negatives (only some) exhibit lighter edges, where the images looks like its fading away at the left-right sides of the 6x6 negative. I have tried many things to help me identify the problem and cure it to no avail. The whole lens-body-back is a year and half old, checked a couple times by the official Hassy guy in Athens and the negatives receive all the attention that a 120 spool needs (away from bright light sources, etc). It also happens on many films so it must be the camera, even though I am puzzled why the technician wouldn't see the problem. You can take a look at a few images in my gallery that show the problem, such as the "Jump" and "Fishing Boat in Martinique" and the "Grandmother". Any ideas?