Re: [APML] Building M31

[Alan Voetsch <alanv12952@yahoo.com>]

Hey Wei-Hao,

Wish I knew how to pronounce your name, I'd guess this one: way-how?

--- Wei-Hao Wang <whwang@gmail.com> wrote:
> a) Bring all images to identical (or at least similar) brightness,
> color, and contrast.
>     This can be done automatically in either PhotoShop CS (the match
> color function)
>     or in Registar (the calibration function).
> b) Make duplicates of all of them and turn the duplications into
> grayscale mode.
> c) In all the grayscale images, select the same background regions
> where there 
>     are no stars and nebulas.  Measure the background rms (standard
> deviation).
>     This can be easily done in PixInsight LE (the statistics
> function).
> d) Combine the original color-matched images and weight them
> according to the
>     inverse of the stddev square.  Such weighted composition could be
> done in 
>     PhotoShop or PixInsight LE, but is the easiest in Registar.

This points out to me how little I know about Registar. I have meant to
study the documentation, but sometimes time does not allow what we want
to do. Along with experimenting in PS, I must spend more time with
Registar. I have not bothered to do any calibrations at all, because
(as usual) I have no understanding of what they do, or how to use them.
Another project for the Winter I guess.

Thank you for the input,
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


		
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