Telescope: Orion 80ED apochromatic
refractor at f/7.5
Focus: Prime focus
Filter: Astronomik Hydrogen Alpha
Mount: Vixen GPD with Skysensor2000
Camera: Modified Canon EOS 300D, at
Guiding: 700mm refractor guidescope,
SAC7 camera, autoguided with Guidedog software
Exposure: Total 86 mins (43 x 120s)
Date: 30th July 2005
Processing: RAW file conversion,
Offset and Dark subtraction, flat fielding, registering and stacking done in
IRIS. Only the Red channel was used. IRIS pre-processing almost
all automated with AutoIt scripts. Curve stretching in Photoshop CS.
Background gradient removal in IRIS. Noise reduction in Neat Image.
Acquisition was managed by GADFly, an AutoIt script I wrote to automatically
nudge the position of the guidestar every few exposures. This is done
to avoid noise pattern build-up in the sky background. In this case,
some pattern did appear in the background - probably did not move the
guidestar enough during the exposures.