From: "Alan Friedman" <alan@greatarrow.com>

Date: April 11, 2007 8:04:33 AM MDT

To: <Astro_IIDC@yahoogroups.com>

Subject: Re: [Astro_IIDC] First Jupiter of '07

Reply-To: <alan@greatarrow.com>

HI Jim -

---------- Original Message ----------------------------------

From: "jimchung2338" <jim_chung@sunshine.net>

http://tech.groups.yahoo.com/group/Astro_IIDC/files/Planetary/

JupiterApril10.jpg

Alan:  how do you combine R+G for luminance?  I actually thought my B + G were 

the better images, R was much dimmer and less contrast.

I wasn't able to open the file when I tried this morning.

To make a combined R/G luminance, prepare and process each image and then 

place them in different layers in a Photoshop document. Align them, using the 

features rather than the disk edge to minimize the effects of rotational blurring if 

any. Then merge them by reducing the opacity of the top layer - 50% would be 

obvious, but you can a different percentage if that produces a better result. Once 

you are happy with the result, save a working copy and flatten the layers to make a 

final luminance image. The luminance image is registered on top of an RGB image 

in the same manner. The layer mode is then set to "luminance." 

Alan