Whatever scanner you choose, you should bear the following in
mind as rough guidance (I generalize here; there are always
exceptions):
- PMT-based drum scanners are better than CCD fi lm scanners, and dedicated fi lm
scanners are better than fl atbeds with fi lm scanning attachments. - Drum scanners aside, all fi lm scanners and fl atbeds are CCD devices.
- Check the bit depth for CCD scanners. This refers to the number of bits used to
represent the color of a single pixel in an image. Higher is better (as it is with
cameras), and most scanners are now 12–16 bits. Don’t buy a CCD scanner with
a bit depth lower than 12 bits. - Check the optical resolution. Anything around 4000 PPI from a fi lm scanner
will recover most all useful data on the fi lm. Some fl atbeds are quoted with
huge pixel-per-inch fi gures, but these can be misleading, with real detail resolve
being compromised by lens quality, focus accuracy (particularly for fi xed-lens
fl atbeds), and light bleed between adjacent pixels. I’d pitch my 4000-PPI
drum scanner against any CCD-based fi lm or fl atbed regardless of the latter’s
quoted resolution. - The latest generation of fl atbeds designed for fi lm, like the best of the Epson Perfec-
tion range, is probably good enough for most uses if used with care.
AB
FIGURE 6.9A and B A shows a dedicated 35-mm fi lm scanner and B a fl atbed scanner. Both use CCD arrays to “read” fi lm and convert it to bits
that can then be manipulated in a computer. © Ole Røsset/iStockphoto (A) and © Jeffrey Schmieg/iStockphoto (B)
SCANNING FILM 117