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Another M81/M82 in RGB


SteveL
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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)

20110307_m81_m82_1024.jpg

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Nice! I see you caught that blue "magellanic" cloud below M81. It will be interesting to compare this with my 32x420s from the LX10/FR/450D one-shot-colour combo.

Does you stack show an even FWHM score? There may be the odd worse frame that is dragging you down.

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I think I just over processed it... am tempted to go back and start again. I did manually inspect each frame and rejected 8x600s subs that had various issues. The sky quality really took a nose dive in the early hours of the morning, so much so that I thought the drop in temperature had shifted the focus point, but at the end of the session, I stuck the Bahtinov mask on and it was still bang on.

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rejected 80 minutes... that's more than most of my entire sessions! wow!

I noticed Tuesday morning that my sky background (from DSS Live) started an inexorable climb from about 3:30 am onwards.

Do you find that you have to rebalance the mount load after a meridian flip?

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Any M81 image with Holmberg IX in is always onto a winner, but I see what you're saying about the noise. TBH the skies weren't great on Monday but that's still pretty nice mate :(.

Tony..

Edited by Whippy
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Do you find that you have to rebalance the mount load after a meridian flip?

I know I am supposed to, but never had any issues so far by not doing it.

The skies werent great, but it was clear, looked like it would stay that way all night, and so I grabbed all the stuff and went out. It was a bit hazy even to start with, but it was just great to be outside imaging for the first time in nearly 2 months!

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stunning detail steve...and there is some flux coming through too....im seeing it everywhere at the moment :(

Bet you are with that 12" hoover Peter!

Good detail in the Cigar Steve especially, not easy targets with OSC I find.

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