Re: [APML] PixInsight questions ( was:Two New Images)

["Carlos Milovic F." <cmilovic@yahoo.es>]

> When dividing
> the flat, I usually set the Midtones between 0.992-0.994. Perhaps
> this is leading to my lighter backgrounds.

I think that the midtones value has nothing to do with the background value. If you do things propperly, the background must have the same vale as the median of the original DBE result (in average).

If you disable all the rescale checkboxes in PixelMath you'll see only that the outern regions become lighter and the central ones lighter, but there will be no color shift (if you had not a color gradient) or lightering of the background.

 

>I subtract the flat. I have not looked over Carlos's method yet. But on
>the 2 I have run through, I also get lighter backgrounds.

 

If you substracted the illumination model, and selected rescale, then there is no correlation between the model and the final brightness of the background. It will depend mainly on the image's noise and the presence of totally black pixels.

 

 

 

I believe the
program matches the darker vignetted areas to the lighter parts. I
wonder if there is any way to match the lighter parts to the darker
parts, and if this can be done by adjusting any settings? Any thoughts
here?

Thanks,
Alan



SCT Astrophotography: http://www.pbase.com/avoetsch/astrophotography
FS-102 G-11/Gemini: http://www.pbase.com/avoetsch12952/tak_fs102
& http://www.pbase.com/avoetsch12952/fs102
& http://www.pbase.com/avoetsch12952/takpf



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Regards,

Carlos Milovic F.
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 CMF
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