filmscanners: Stellar ghosts and Nikon Coolscan IVED (LS40)

[Harry Lehto <hlehto@oj287.astro.utu.fi>]

When I scan an image containing black sky and bright stellar images with a
Nikon Coolscan IVED (=LS40) , then close to the edge of the field every
bright (saturated) stellar image has a faint ghost image separated from
the main image (by 20- 40 pixels).  All the ghost images are on the
"outside". These are not present in the center 1/3 by 1/3 of the field.
Multiscanning with vuescan appears to make these features more striking
because it reduces the background noise but not
these images.

This happens both with the Nikon software, Vuescan and with Kodachrome,
Ektachrome and Fujichrome. Moving focus manually does not change matters
significantly in regard of these ghosts.

The things look like reflection, they are quite different from the
"normal" optical distortions visible also close to the edge of the field.
Is this a design flaw? Is it present in other scanners too? Is there any
way to get rid of these ghosts other than by manual editing?

I have put 2 images on my web pages so that you can get an idea of the
phenomenon at
www.astro.utu.fi/~hlehto/nikotest/crop0016.JPG and
www.astro.utu.fi/~hlehto/nikotest/crop0020.JPG
Yes, the vuescan is still an evaluation copy.

Regards
Harry J Lehto