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Re: [APML] Orion Mosaic preview
>The major difficulty I had in processing these images is vignetting
>correction. [...]
>What I plan to do is, to borrow the flat-field technique used by
>CCD guys. Take a shot of some uniform brightness target and use
>this image to correct the vignettign pattern. Because film is not
>linear, I'm not sure how good the results will be.
Hi
How about taking several images of without interesting objects in them and then make a "super-flat"? If you take them all with the same exposure time (and of course the same as your object's), and use an adecuate blending method (perhaps an average with sigma clipping) perhaps you could reproduce the optical system's illumination pattern and the film's response... Of course you'll have to scan all the images the same and work with raw images (perhaps you can do first some kind of "bias").
What do you think about?
Regards,
Carlos Milovic F.
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Astro & Photo - CMF
http://www.astrophoto.vze.com
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Visita "AstroFoto", el foro de astrofotografía en español
http://espanol.groups.yahoo.com/group/astrofoto
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