Re: filmscanners: Dat doggone dust!!!

["Dana Trout" <dana@troutcom.com>]

I am assuming the tram lines are dark after you have inverted the color
negs to see the image as a color positive. If my assumption is correct,
there are several sources:
 1. If the tramlines are quite defocussed, it could be dust on the
fluorscent tube(s) (the old tran head used two, the new model uses only
one) and/or the white diffuser in the channel holding the fluorescent
tube(s).

 2. If the tramlines are only a few pixels wide, the more likely
culprit is dust on the white calibration bar that is on the underside
of the glass platen (the glass on the body of the scanner). The
calibration bar is between the narrow window at the front and the main
window used for scanning.

N.B. I've also found dust on the mirrors in the scanner -- depending on
which mirror is dirty the tramlines can range from defocussed (the big
mirror at the beginning of the folded lightpath) to very defocussed
(the smallest mirror, which is at the end of the path and is closest to
the lens). These are front-surface mirrors so be very careful that you
don't abrade them if you decide you want to try to clean them.
  --Dana
----------
From: david/lisa soderman <scapes@wi.net>
To: filmscanners@halftone.co.uk
Subject: filmscanners: Dat doggone dust!!!
Date: Sunday, July 08, 2001 7:16 PM

Hello!
I have a umax powerlook 111 with the tranny adapter.  I mainly use it
to
scan 6x6 color negs with VueScan.  When the scanner was new, everything
was
fine and I was a happy camper.  But over time, the dust began to
torment me.
"Regular" dust I can cope with.  I'm talking about the kind that causes
black lines that run straight down vertically...from top to bottom ( or
bottom to top).
I've removed the glass from the tranny adapter - and cleaned both
inside and
out.  That improves the problem, but the lines usually get shifted to
other
locations within the frame.

This has become very frustrating.  Are there other areas that I should
be
cleaning?  If so, where?  Any insight would be greatly appreciated.
Thanks in advance!

-david-  <><