Telescope: Celestron 9.25"
Schmidt-Cassegrain at f/6.3
Focus: Prime focus
Filter: Astronomik Hydrogen Alpha
13nm FWHM, Celestron LPR for the RGB image.
Mount: Vixen GPD with Skysensor2000
Camera: Modified Canon EOS 300D, at
Guiding: 700mm refractor guidescope,
SAC7 camera, autoguided with Guidedog software
Exposure: Total 80 mins (20 x 240s)
Luminance, and 44 mins (22 x 120s) RGB.
Date: 1st May & 1st June 2005
Processing: Reused the H alpha image
from 1st May. For RGB, RAW file conversion,
Offset and Dark subtraction, flat fielding, registering and stacking done in
IRIS. Used the ASINH function to enhance colours. Curve stretching and a
little unsharp masking in Photoshop CS. The RGB was composited with the Luminance image using a
technique described by Rob Gendler
(Method 2). Noise reduction
in Neat Image.
For the H alpha - It was a hot, humid (29
deg C, 90%) and windless night. Transparency was middling to poor.
The RGB was also taken in conditions of poor transparency - in fact
high cloud terminated the imaging session.