From: "Tim" <tjp314@pacbell.net>

Date: January 11, 2006 4:21:36 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: Eskimo Nebula image uploaded to files

Alan:

Yeah, kind of a peach overtone, particularly on Jupiter.  Mars wasn't too bad.  But for the 

most part, my SCTs do better on the planets with a ccd.  Blasphemy, I know.  Visually, the 

refractor does a fabulous job, but the eye/brain can accomplish a lot when dealing with 

chromatic abberation.  

It may be that today's ccds are so sensitive in the blue that the halo in an achromat is just 

too objectionable.  Stars don't seem to be so big a problem, though without the filter the 

halo is there (and is quite large with respect to the star image).  

One way it "helps", though, is in focusing.  Stars and planets take on a greenish cast on 

one side of focus,  and a magenta cast on the other (don't remember which is which, but 

green should be inside, I think), and the "range" of good focus is very narrow.

-Tim. 

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

I haven't used it in a while (bought one for the mars 2003 apparition), 

but I remember the Baader Contrast Booster filter as imparting a warm 

yellow cast to the image?

Alan

First, I took both the FR and the filter off, but the 

residual color was very

objectionable, such that I bet I'd get nothing but blue-appearing 

stars if I imaged that way.

It sounds like you color balance is possibly whacked then?