LRGB of M31 in Andromeda
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|Telescope||Nikon 180mm F2.8 ED Lens at F2.8|
|Camera||Class 1 NABG ST-8E, Second cooling stage enabled (all images taken at -18C).|
|Camera Control Software||MaximDL/CCD 2.03 beta|
|Location||My light poluted yard in San Jose, California|
|Date||September 27, 1999|
|Sky Conditions||Slightly above average transparency , moderate seeing.|
|Exposures||5 minutes Red, 5 minutes Green, 10 minutes Blue,
all at 2x2 binning. I also did a set of full resolution (1x1 binning) luminance images (6x10 minutes) but I didn't notice I was overexposing the core, not to mention a few dozen stars! So, I used the Red exposure (after DDP) as the Luminance because it had the best S/N. Because of this the resulting image is half of what I was trying for.
I used standard RGB Gel filters in front of the camera lens. Not as elegant as a color filter wheel but it alowed the lens to come into focus. I placed the SBIG IR filter inline between the lens and the ST8E with a male-to-male adapter.
|Image Resolution||Images were taken at 765x510 (2x2 binning)|
|Processing||All frames were corrected with bias, dark, and flat field frames. I used heavy DDP (20%) on the luminance layer to bring out the core. For final color balancing (it's still not perfect) I used Photoshop 5.|