M81 (left) and M82 Galaxies
(Click here for full sized image)
Takahashi FSQ-106N f/5 4-element fluorite refractor
II German Equatorial Mount
Barbara Instrument Group ST-8E NABG CCD camera (1530 x 1020 pixels, 9 x 9mm, monochromatic, 16 bit, 13.8 x 9.2mm array)
color filter wheel with clear and IR-blocking red, green and blue dichroic filters
Saturday, December 26, 2000
Joshua Tree National Park, CA
Approx. 3500', OAT +34F.
exposure time: 130 minutes. (14x5 minutes luminance, 4x5 min. red, 4x5
min. green, and 4x5 min blue)
Stacking: White-light luminance behind RGB tricolor image.
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.