RE: [APML] Background banding

["Jon Kolb" <jkolb@datawest.net>]

Hi Peter,

> I've recently been photographing at the f5.4 prime focus of my TV
NP101 using Kodak elitechrome 200 and > had my transparencies developed
at a local professional lab. I've noticed faint green and magenta bands
> in the background running along the long length of the frame when the
image is contrast stretched in PS. > The bands are not detectable on the
original film. See image http://www.thecarsons.demon.co.uk/M33.htm 
> and http://www.thecarsons.demon.co.uk/M31.htm on my web site for
examples.
> Can anyone tell me if they are in the film or caused when scanning
using my Minolta dimage Dual 3 and 
> how best to get rid of them.

I've had a similar problem from time to time, but the bands aren't as
sharply defined as yours.  Unfortunately, I haven't found an effective
means of removing them without spoiling the rest of the image.

You can determine if it's the scanner by rescanning the image and
reorienting the slide so that the bands would have to show up in a
different place in the image if the scanner were putting them there.
I've ruled out the scope (happens with difference scopes or lenses),
film (happens on different types and rolls of film), camera (happens
with 3 different cameras), and scanner (orientation change didn't change
location of bands), and now believe it is the lab, so I'm going to
switch labs next time and see what happens. 

Sincerely,
Jon Kolb
Adventures in Astrophotography
http://home.datawest.net/jkolb/
Life Member, International Dark-Sky Association
jkolb@datawest.net




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