Re: filmscanners: Stellar ghosts and Nikon Coolscan IVED (LS40)

[Julian Robinson <julian@austarmetro.com.au>]

I am not sure if you picked up this post by Ed.  I agree that it sounds 
very like an exposure problem.  As well as Ed's suggested Vuescan solution 
you could try Nikonscan / Extras / Autoexposure / Lowcontrast low key (or 
lowcontrast neutral)

I hope you can sort this otherwise it seems to be a serious deficiency in 
what one hopes is a great scanner.

Julian

At 19:56 10/05/01, you wrote:
>In a message dated 5/10/2001 3:20:02 AM EST, hlehto@oj287.astro.utu.fi writes:
>
> > 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.
>
>The CCD might be over-exposed near the star, causing CCD
>charge bleeding.  It might also be some kind of optical side effect.
>
>Try turning off "Device|Auto exposure" and set "RGB exposure" to 1.0.
>
>Regards,
>Ed Hamrick


Julian Robinson
in usually sunny, smog free Canberra, Australia