M42 The Great Orion Nebula
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This image was Santa Barbara Instrument Group's "Image of the Month" for February 2001
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 IR-blocking red, green and blue dichroic filters
Date: Saturday, November 25, 2000
Location: Joshua Tree National Park, CA
Elevation: Approx. 3500', OAT +37F.
Total exposure time: 60 minutes. (4x5 minutes red, 4x5 min. green, and 4x5 min blue)
Color Stacking: Green luminance behind RGB tricolor image. 60 minutes of deep red, Hydrogen-alpha filtered exposure was shot but not used in final composition. (I felt the green channel had better contrast and produced a more interesting composition than I could achieve with the H-a luminance data.)
Processing: Dark and flat cal, mean (not median) combining and DDP (on luminance) with MaxIm. LRGB stacking, final level adjustments, color balance, blooming repairs/reconstruction, crop and security with Photoshop.