Horsehead NGC7293
The Helix Nebula

(Click on image for Full Resolution)

Date: September 13, 2003
Exposure: HaRGB : 14400:3600:3600:6000
12 x 1200s Ha, 6 X 600s R,G & 10 x 600s 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, 16-1200s, 20-600s darks median combined, alignment, normalization, and color combining. Photoshop for Ha+R G B combining, final balance and web conversion. The light pollution was very bad on the green and blue images as the nebula is very dim and exposures over several nights with changing conditions only adds to the complexity. I went for detail on this one and as a result, the noise level is higher than I would have otherwise posted.
Conditions: Above average, Mag 4-4.5 Skies, very clear and 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 3 nights to get the almost 4 hours of Ha data needed to have good S/N. The RGB images were also taken on the same nights. R and G before the meridian and B after.