Hmm rather than investigating it closer myself, I'll just "axe" here...
Scanning 4x5s on my trusty 5-6 year old Epson 4990 using the stock holder which places the two 4x5s horizontally on the platen. I am getting a couple pixel wide black line across my scans, which means something is dropping/blocking on just one small narrow portion the moving CCD bar. I don't see anything dark or messed up here.
Anyone have similar experience? Any advice?
Bookmarks