I normally take my C-41 colour film to one of the nicer photo stores in town to be processed and often printed. In the last little while I've been noticing a "crust" on parts of images that are very bright, and often against darker areas. The edges of the bright part often look very rough, and this hadn't started happening until recently, using the same films I normally do.
It was noticeable on prints, and I talked to the guys at the shop about it. We looked at my negatives with a loupe and couldn't see what we were seeing on the prints. So the tried tried doing another print of a couple of frames, yielding the same results. Eventually, they attributed it the fact that I was using expired film and I was slightly overexposing.
However, I'd been using that same film and been having it processed that same way for quite a while without having problems, and now I see it on nearly every roll (not every frame, only those with really bright parts.) So, instead of ordering prints the next time I went in, I asked for the negatives to be scanned and burnt to a CD, thinking that since we couldn't see any problem with the negative that the negative scans should be perfect. But that wasn't the case, the scans showed that same "crust" only it was much more visible at the higher resolution. It must be mentioned that I've had the same issue on different types of film too.
Here is a good example (resized to 600px wide):
And a cropped section from the full resolution scan:
Anyone have any ideas? They seem to attribute it to my expired film (as an easy-out I suppose), but since I've had the issue with several films, and because it popped up out of nowhere, I don't the that's the case.