Quote Originally Posted by Dan Fromm
"Softening in the corners" isn't what most of us think of as vignetting. Vignetting usually means dark corners. Here's an example. Very compressed, looks awful, should make the point anyway.
What was happening to my negs was a very very subtle version of this example. The only way I noticed it was because I photographed something on a very green lawn and the grass at the bottom corners of the frame (vertical orientation) was a bit darker.