filmscanners: film flatness in Nikon 4000

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

Art,

well... I've got a liquid gate for my DeVere's, and I've got carriers with
no glass, regular glass, anti newton glass, and vacuum coated anti newton
glass (best)
I use $2500 Apo-El-Nikkor lenses imported from Japan, (unavailable here)
(none of the others are really Apo's) and I would *never* make a serious
print without glass of some sort holding the film flat. (35mm or 10x8")
sorry but all my tests show the opposite of yours, and any tiniest
intereference from the glass is vastly more than compensated for by the
*dramatic* improvement in sharpness over the whole film plane, but
especially the corners/edges.
keeping the glass clean is not such a problem, and I replace it once every
few months anyway.

But then I work very large (40x50" colour prints are average), so things do
get hyper-critical.  Then again, that's why I'm interested in a 4000 dpi m/f
scanner!

Before this gets too OT, see my next posting: (follows)


Date: Sat, 31 Mar 2001 21:54:29 -0800
From: Arthur Entlich <artistic@ampsc.com>
Subject: Re: filmscanners: film flatness in Nikon 4000

(snip...)
Yes, enlargers can be bought with glass neg carriers, but guess what,
they actually degrade the image result. I've tested this with my own
enlarging system. (Besseler, Nikkor lenses) You are adding 4 new
surfaces, none of which are perfect in surface or color, even if they
are optical glass, and all of which are very close to the focal point at
the film plane.  Add to that internal reflections within each sheet of
glass, potential dust scratches and dirt, if they are not perfectly
clean, and potential damage to the film.  Glass sandwiching is done
sometimes with a viscose wet gate, to help reduce the internal
reflections of two of the surfaces, and having the outer surfaces far
enough away from the film plane to me out of the focal range.  But using
a glass carrier with a 35mm film scanner doesn't make it, as far as I'm
concerned.  Further, it requires removing the film from slide mounts
(more potential damage).
(snip)...