M81 (left) and M82 Galaxies
(Click here for full sized image)
Telescope: Takahashi FSQ-106N f/5 4-element fluorite refractor
Zeiss II German Equatorial Mount
Santa Barbara Instrument Group ST-8E NABG CCD camera (1530 x 1020 pixels, 9 x 9mm, monochromatic, 16 bit, 13.8 x 9.2mm array)
CWF8 color filter wheel with clear and IR-blocking red, green and blue dichroic filters
Date: Saturday, December 26, 2000
Location: Joshua Tree National Park, CA
Elevation: Approx. 3500', OAT +34F.
Total exposure time: 130 minutes. (14x5 minutes luminance, 4x5 min. red, 4x5 min. green, and 4x5 min blue)
Color Stacking: White-light luminance behind RGB tricolor image.
Processing: Dark and flat cal, mean (not median) combining and DDP (on luminance) with MaxIm. LRGB stacking, final level adjustment, color balance, blooming repairs, crop and security with Photoshop.