[filmscanners] Re: "Halo" Effect

["Arthur Entlich" <artistic-1@shaw.ca>]

I can think of a few potential causes.  One may be just the way you have
the software set up in terms of gamma or contrast, however, this can
also occur due to a dirty optical path, due to dust, smoke, or other
household pollutants coating the lens, and mirrors or other optical
surfaces within the scanner.  The SS4000/+ is very "open" to the outside
environment, and I keep the one I use under a static free plastic cover
when not in use.  There are no smokers here, and it is a good distance
from any kitchen residue.

Unfortunately, film scanners aren't easy to clean oneself in most cases,
so if this is the case, you may need to have it professionally cleaned
by Polaroid.  I don't know what they charge.

Art

Robert DeCandido, PhD wrote:

> Hello All,
>
> I have a Polaroid Sprintscan 4000 (not the Plus version) and am using
> Vuescan.  When I scan a slide (either Kodachrome or Provia/35mm), the
> white areas (such as a building illuminated by the sun; or pages of an
> open book) in the scan will exhibit a "halo" effect.  This appears as
> a kind of a whitish or even greenish glow surrounding the white object
> in the scan.
>
> My questions are: Is anyone else seeing this or getting this effect on
> their scans?  Is this something gone wrong with the scanner?  Is it
> something that different scan settings in Vuescan can correct?
>
> Using Knockout 2.0 I can correct most if not all of the "halo" or
> "after glow."  However, if someone can set me straight regarding how
> to solve the problem before the scan, I would be most appreciative.
>
> Thanks
>
> Robert DeCandido
> NYC
>
>
>


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