From: "Raoul Schlesser" <gr842@yahoo.com>

Date: November 14, 2005 5:24:19 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: mars at 20 arc seconds

Thanks Alan,

the blue cast seems to be the trickiest part in my opinion. If you compare images from 

different people, there seems to be great variability in how much of bluish features they 

capture, even on the same day... I've found that differences in sharpness of the color 

channels seem to create artifacts near the limb, so I'm always wondering how much of the 

blue stuff is due to artifacts... not all  "morning clouds" may be what they seem ;)  

That being said, I do see bluish features through the C9.25 at high magnification as well, 

so some of what appears blue must be real. This is the first season that I'm imaging 

planets with a monochrome camera, so I'm naturally supicious about my own stuff. I have 

more data to process than time permits in the moment, but here's a very preliminary IR-

RGB image that I'e been working on:

http://home.nc.rr.com/rschlesser/mars20051107.jpg

Perhaps you guys can give me a few hints..

Thanks,

raoul

--- In Astro_IIDC@yahoogroups.com, Alan Friedman <alan@g...> wrote:

Thanks Raoul - I tried to retain the color values from the RGB 

composite as much as I could when adding in the luminance image. There 

was a slight bluish cast to the albedo features which does seem to 

carry through in the eyepiece view through my scope.

Alan