March 9, 2011

M81/M82 in RGB

Given that most of my images are wide field, when the winter objects start to slide slowyly into the western horizon, its time to bring out the 190 Mak Newt again, and try to find something a bit smaller to image.

My last attempt at M81/M82 was a dismal failure… it was focussed and on target, but with a side by side bar and a seperate guidescope, differential flexure limited my exposures to 5 minutes, and the final image lacked any real colour other than grey/green :)  This time round, I am armed with a TS 9mm OAG, so less weight on the mount and much better tracking.

So here it is! I still think its a bit noisy (both in the background and the finer detail), especially at the larger size, but I was able to extract and enhance much more colour information this time round. The image below is a crop from the central region, as there is an odd gradient on the left and right sides of the full size image. Could be a flats issue, but more likely ligh pollution or sky glow gradient caused by imaging on either side of a meridian flip. (Had the same issue with M101 at SGL5 last year)

Mount: EQ6 via EQMOD
OTA: Skywatcher 190 MakNewt @ f/5.3
Guiding: TS OAG + SX Lodestar + Maxim
Imaging: Starlight Xpress M25C + MaximDL, 28 x 600s, Hutech LPS filter
Orchestrated: CDD Commander
Stacked: DeepSkyStacker
Post Process: PSCS2 + PixInsight

(Click on image for larger version)

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