I don't know the current process of digitizing anime (when 
is it scanned?), but one reason I dropped more money for a 
excellent mid-level scanner was specifically for my cels.
^_^ A FAST scanner which wouldn't leave the cel in the light
for too long (my Epson scans at 200-300dpi in about 10 seconds).
Umax is probably one of the worst scanners to use for this
because it's soooooo sloooooow. I think it's just a matter of
exposure time and intensity. Compared to framing in non-UV-
proof materials and leaving in the sun, scanning is nothing.

Just my thoughts.