Telescope: Orion 80ED apochromatic
refractor at f/7.5
Focus: Prime focus
Filter: Astronomik Hydrogen Alpha
13nm FWHM, Astronomik RGB.
Mount: Vixen GPD with Skysensor2000
Camera: Artemis 285 CCD camera
Guiding: 700mm refractor guidescope,
SAC7 camera, autoguided with Guidedog software
Exposure: Total 150 mins (30 x 300s)
H-alpha, 33, 39, 93 mins R,G,B.
Date: 6th & 7th July 2006
Processing: For all frames, offset and flat
fielding, registering and stacking done in IRIS. No dark frames.
RGB combination is first done in IRIS, and star colours are calibrated with
a G2V star. LRGB compositing, curve stretching, Levels, Smart Sharpen in Photoshop CS2.
LRGB compositing is through the process of
Corrected LRGB" as described by Steve Cannistra. The R component
of the RGB is first mixed with H-alpha in Photoshop and then recombined into
a new RGB. The Luminance layer was H-alpha mixed with desaturated RGB
and with a correction layer whose opacity is reduced in subsequent
iterations. Pls see the link above for details.