From: Mark Gaffney <markgaffney@me.com>

Date: February 15, 2010 6:33:50 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Mars: RGB vs L(IR)RGB

Antonio, 

If you have Astroplanner v1.6 on your Mac, there`s a list of (21) G2V stars (stars of same spectral type as the Sun or roughly white coloured) in the download user contributed plans section. v 2 has it too but it is only in Beta testing stage-I think you can still apply to test v2 if you wish. I`ve done so quite a while ago. Astroplanner costs a small fee & this entitles you to v 2 when it`s available. It`s so much more than just the G2V stars list though! I also have a list of 159 G2V stars in SkyTools 3 Pro on my PC which was added at my request by Greg Crinklaw. It`s considerably more expensive & only for PC`s. 

Mark.

On 15/02/2010, at 6:11 PM, aa27100 wrote:

Thanks Alan (and Willie, Milton)!
How do you weigh the color channels captured through RGB filters? I usually tend to calibrate the white point on the "white" feature of the image (polar cap on Mars, rings on Saturn, white bands on Jupiter). Maybe taking a picture of a sunlit white sheet of paper is a better way to have an absolute calibration... (not sure about what to do with the IR)
Thanks for your valuable suggestions!

Antonio
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