This is the same combination of 6 exposures each at 30, 60, 120 and 300 seconds - for a total of 51 minutes at ISO 800 captured by ImagesPlus, but combined using IP's "HDR Combine" operation.
No darks, flats, bias frames. Post processing: HDR Combine using Adaptive Add and Multiresolution sharpening in ImagesPlus and curves adjustment in Nebulosity2. Final contrast adjustment and resized in ThumbsPlus.

Inadvertently, the camera was left on the JPEG setting (rather than the prescribed RAW acquisition mode). And who says you can't image at f/10?

Telescope configuration: EdgeHD 9.25 (2350mm, f/10) and no focal reducer, imaged at medium resolution (3456x2304), yielding an image scale of 0.93 arc-seconds/pixel and a FOV of 21.7x32.6 arc-minutes. Focused using a Bahtinov focus mask. Mount: Losmandy G11 w/Gemini. Autoguided with a Lodestar autoguider connected to a Stellarvue 50mm finderscope and a Celestron 2x Barlow and PHD autoguiding software.


20110125_M42_30-60-120-300-CombAdpHDRAdd-mrs-x50pct.tif