Another Go At Part Of M42...

[Ian McCallum]

I had another go at part of M42, last night.  The setup was the usual SW ST120 achro, with a ZWO ASI224MC camera (fitted with Baader Contrast Booster and IR/UV cut filters).  I took 20 x 30sec subs and the same number of darks, at the same exposure and gain settings, etc.  I used Unity gain with an offset of 140, with a 2 second pause between exposures.  I used a Bahtinov mask to get a sharp focus on Betelgeuse.