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

[Herm <hermperez@worldnet.att.net>]

Harry, you have a very mild case of coma induced by the scanner..its very mild,
dont worry about it. I have seen it when scanning astrophotos with an HP
Photosmart scanner, but to a much worse degree..you can see an example at (turn
up monitor brightness first): 

http://home.att.net/~hermperez/this_is_a_comparison_between_two.htm

Herm


Harry Lehto <hlehto@oj287.astro.utu.fi>  wrote:

>On Fri, 11 May 2001, shAf wrote:
>
>>      To me this implies the problem is with respect to the film ... a
>> problem with the scanner, yes ... but the problem rotates with the
>> film.  If I were to guess, and try something different ... I would
>> snip off the sprocket holes ... possibly "all those edges" are the
>> source for the internal relections(???)
>
>The slides are framed. The ghost does not rotate with the film (it rotates
>in respect to the stars) - am I choosing the right words here?
>I have scanned two  more pictures
>http://www.astro.utu.fi/~hlehto/nikontest/crop0041.jpg
>Here the slide is put in the scanner as should and when viewed with
>vuescan this image is at the bottom, somewhat to the right. You can see
>the ghosts below the two stars in the field.
>Then I turn the slide counterclockwise by 90 degrees. Now the scene is on
>the top edge of the vuescan window and again on the right side. Now I get
>http://www.astro.utu.fi/~hlehto/nikontest/crop0042.jpg.
>Now you can see the ghosts pointing up on the screen.
>Exposure is set manually on 1 sec. Gamma curves are used in processing.
>
>This image is taken with a 300mm  lens, on EPH ISO 1600
> - the other images mentioned earlier were taken with a 50mm lens and
>Kodachrome 200.
>
>Thanks for all the suggestions and tips I have had from this group.
>
>Regards
>Harry
>
>
>
>