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Re: [APML] M33 TV-85, ST2000XM
Hi Broose:
Here's a quote from the SBIG forum, where Don mostly hangs out
Bert
2003-01-02
At the request of several people, I have added the SBIG ST-2000XM
camera to my RGB Weight Calculator prior to its release in a few
weeks.
This camera has the Kodak KAI-2000M CCD with a very different quantum
efficiency curve than most others. It peaks in the blue-green region
rather than in the red to improve relative blue sensitivity. Here are
some R:G:B weights that I just calculated that would give you a good
white-point adjustment (~solar analog) for proper star color balance
(assumed SCT telescope, SBIG/Custom Scientific RGBs, 70 deg elevation
and no LPS filter):
Camera Red Green Blue
ST-10E 1.22 1.00 1.73
ST-2000XM 2.27 1.00 1.26
These weights represent equal time exposures. The RGB Weight
Calculator will also take your actual red, green and blue exposure
times and recompute the weights that you should use.
As expected the red weight must increase for the ST-2000XM due to the
lower sensitivity of this CCD in the red. The blue must decrease due
to its higher blue sensitivity (relative to green and red) of the
CCD.
If anyone has taken solar analog measurements on a G2V star with this
new camera, would you be willing to share the results? I would need
to know your telescope, object elevation when you took the image, and
filter brand. You can e-mail me privately at dsg@optical-
solutions.com or at my Yahoo e-mail listed here.
Hope this proves useful.
Waiting for Clear Skies in Sacramento!
Don Goldman
www.astrodon.com
----- Original Message -----
From: <Skyloverz@aol.com>
To: <astro-photo@seds.org>
Sent: Monday, September 22, 2003 4:44 PM
Subject: Re: [APML] M33 TV-85, ST2000XM
> Thank U Bert
>
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