Re: [APML] Adjusting mosaic frames

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

Yes, you should color neutralize and match the black space background to the
same value of both sides of the mosaic, prior to assembling or stacking. I
normally set every frame to RGB 40-40-40 (prior to stacking and combining the
mosaic). If you have the ability, try to do this in 48bit mode to minimize
posterization.

Before the final step in the mosaic assembly, compare both frames side by side
in photoshop and see if they match in general brightness and color (they
should).. then mosaic. Final constrast, curves and brightness adjustments are
done to the assembled mosaic. 

I have a couple of good mosaics in my web page:

http://home.att.net/~hermperez1/NAN_mosaic.htm

This NAN/Pelican mosaic shows a dividing line between the two frames, why?..
because after matching the two frames by the numbers I fiddled with the Pelican
side until it looked "right" (the lesson is to trust the numbers), later on I
learned that NAN is supposed to be brighter than the Pelican.. anyways you can
see the dividing line if you increase your monitor's brightness. I have not
bothered to redo the mosaic so everybody can learn from my mistakes, I always
archive the registed and adjusted frames.

I also did a mosaic of the Sword of Orion area,
http://home.att.net/~hermperez1/sword_of_orion_complex.htm ,  but I challenge
you to find the dividing line in this one (its in the middle of the nebula, left
to rig th).

I use PW to align, and PS to mosaic.. with a feathered edge of course.

I also have a mosaic of the M8 area, its not in my web site but I can mail it to
you.. its 200kb. Its a bit dark (short exposures) but technically very good.

The "numbers" method is the easiest way to do a good mosaic, I wasted a lot of
computer hours trying to do it by the "eyeball" method (g).

"Peter Mumbower" <ngc7331@home.com>  wrote:

>Just to clarify a little more. I have a 2 panel mosaic, with each panel
>having 3 negs to stack.  After I stack them in Registar and assemble the
>mosaic in Registar, I go to Photoshop, where I try to match the background
>for each panel, unsuccessfully. Should I be adjusting the levels in PS
>before I assemble the mosaic?


Herm
Astropics http://home.att.net/~hermperez

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