filmscanners: film flatness in Nikon's

["PAUL GRAHAM" <peegee@btinternet.com>]

Mikael:

don't see what any of that text you quote from Nikon:
        "Coolscan® Film Scanners:
              The Coolscan IV ED, Super
              Coolscan 4000 ED and Super
              Coolscan 8000 ED, take film
              scanning to a new level by..."
(etc)
has to do with the choice of carriers...
I'm not critical of your findings - they are probably true, I just don't
feel it is a total failure on the scanners part, when they give you a choice
of carriers:
If you are just making quick scans for proofs - use the glassless carrier,
but if you are making critical scans for the ultimate 4000dpi results, then
use the glass carrier - that was my point.
It is precisely what all pro darkroom people have done for years, and its
what I do, even with 1000 watts of halogen bulbs shining through a
negative...

maybe other scanners use a brighter lightsource and so gain depth of focus
etc, but this one doesn't. I expect there is some trade made by Nikon
against using tubes for LED spectrum, long life, heat, consistency or ?...
I notice that the recent ZBE Chromira printer, which (like a
Lightjet/Lambda) writes digital files direct to photo paper, is an LED
machine too..

Film flatness is a problem with all scanners/enlargers. Flatbeds don't
suffer so much from it because  the film is pressed against the glass - in
other words - it's glass mounted! Even with high end drum scanners and laser
light sources you have to ensure negative flatness with oil mounting and
pressure rollers etc, so, why should it be any different here as we approach
drum scanner resolutions in desktop boxes?

Nobody in decades of making enlarger negative holders has come up with a
glassless way of holding a negative perfectly flat, the only solution has
been glass carriers, or stopping down the depth of focus to the detriment of
image resolution (and I don't want to get into circles of confusion here!)

paul