Re: filmscanners: Gizmo to make flatbed scan large format film?

[Arthur Entlich <artistic@ampsc.com>]

Wiping the tears from my face, after a really hard laugh... ;-)

More seriously, this idea is not only not funny, but indeed is produced
by many scanner manufacturers.  AT one time it was an option that one
could by separately (often at a way too high cost).

The main problems with using a flatbed scanner for scanning film, in
general, is contact with the glass surface causing Newton rings, and
that most lower end flatbed scanners have compressed dynamic range.

35mm film scanning on flatbeds can also suffer from the scanner having
too low a resolution.  However, medium and large format films can create
a reasonable file size even at 600-1200 dpi.

Better quality flatbeds might have a special drawer which might not use
glass, and a separate optical path and lens for film, and, of course,
better sensors with wider dynamic range.

The problem with scanning films on flatbeds is the need for a light
source which goes through the film from above.  The best method is, of
course, buying a scanner which has a transparency adapter, which plugs
into the scanner, and usually lets the software know a film is being
scanned, and in some cases, but not always, shuts off the reflective
lightsource.  You can buy relatively inexpensive scanners which have
these transparency light sources as add ons or incorporated into the
hood (under $300 US).  These have software profiles for negatives to
remove the dye mask (orange background), which most flatbed scanner
software usually doesn't include.

Not all newer scanners with this feature can scan a full size large
format film.  Newer scanners make use of the "sweet spot" of the scanner
to scan a medium format film (up to perhaps 3" square).  For some
reason, older units seemed to be designed to scan up to 8 x 10"
transparencies/negatives.  You might wish to look on something like
e-Bay for either an older scanner with the adapter, or an adapter for
your scanner, if one was made.

   I have heard of some people successfully scanning large format
transparencies by placing them on the flatbed with the hood open, using
a relatively bright, but diffused lightsource that they track along with
the scan head as it moves.  It would seem to me tricky but possible.
Apparently, you need a bright enough lightsource to overpower the
reflective light, if that can't be shut off.

If your scanner has a transparency top interface plug, you might wish to
look around on the web and see if anyone had mapped it, as there might
be a simple way to put the scanner into "transparency lighting mode".
I have seen this for some UMAX scanners, and I do doubt that IBM made
your scanners, so you might need to find out who OEM'd it for them.

Art



Herb Bauer wrote:

 > Hi everyone,
 >
 > don't laugh too hard, please, but is there something that could turn my
 > flatbed (IBM brand) scanner into a half-way acceptable large format film
 > scanner?
 >
 > Thanks,
 >
 > Herb
 >
 > .
 >
 >