Horsehead NGC896 Horsehead

(Click on image for Full Resolution)

(Click here for the H-Alpha exposure used in the HaRGB composite)

Date: October 20, 2003
Exposure: HaRGB : 14400:5400:5400:9000
12 x 1200s Ha, 6 X 900s R,G & 10 x 900s B
Processing: CCDSoftV5 for image acquisition, MaxIm for RGB combine, image calibration: 20 flats each Ha,R,G,B, dark subtracted and median combined, 30 bias frames median combined, 16-1800s darks median combined, alignment, normalization, and color combining. Photoshop for Ha+R combine, MaxIm for HaR+G+B combining,Photoshop for final balance and web conversion. The light pollution was very bad on the green set, but I may have discovered a processing sequence that gets most of it out for my conditions. Time will tell. The RGB exposures were done with the humidity pegged on 100%.
Conditions: Above average, Mag 4-4.5 Skies, very clear, but the usual 100% humidity after midnight.
Scope: AP 155 EDF @ F/7 on a Paramount ME
Camera: SBIG ST-8XE/CFW-8A, -20°, Custom Scientific 3nm Ha Filter
Comments: This was taken over 2 nights to get the almost 4 hours of Ha data needed to have good S/N. The RGB images were taken on the same night. Located in the constellation Cassiopeia, this nebula is very dim and only approx 27' in size. It is about 1° NW of IC1805.