M101 LRGB

[robin-m]

Now that I have my camera back and we've had a few clear nights M101 was an obvious one as it passes overhead at the moment

Total integration time 6 hrs 20 mins not counting subs ruined by aircraft

L 12 * 10 mins

R 10 * 10 mins

G 6 * 10 mins

B 10 * 10 mins

ED80 @ F7.5 no flattener. Resized 50% for posting

No darks, flats or bias frames used. I may go back and revisit the data when I've taken some but for now I'm done with it. I found M101 really difficult to process and don't feel that I've got it right yet but I'm fed up with it for now.

[Gina]

That's very nice And I know the feeling Though I can't see anything obviously wrong with your image. I had an initial go at M101 with a relatively small amount of data, got fed up with it and took M51 next time (which wasn't much better) and then went back to M101 and collected quite a lot more data. That pretty much transformed it. It's a more difficult object than is first apparent. We need many more clear nights and could do with longer ones - 6 or 7 hours is not really that much data.

[astro mick]

Nothing wrong with that at all.Very nice image.

Mick.

[robin-m]

Thank you both.

I think the reason I'm dissatisfied with it is colour. I found it very difficult to keep the galaxy colour looking natural and retain star colour. I will go back, mask the stars, and process their colour separately which may help but I've played with it for long enough now. Losing a good percentage (~20%) of your subs to aircraft doesn't help either.

One of the junked subs, a 10 min B sub just stretched.

[Gina]

Are you sure that's not one of mine? I have the same problem with the dratted aircraft Somehow I had changed DSS stacking to "Average" instead of "Kappa-Sigma clipping". The latter will remove plane trails.

Three pics to demonstrate this :-

1. DSS Settings
   
2. A stack showing plane trails (with cropping)
   
3. Another stack with KS setting with the exact same set of subs (uncropped)
   

[sologuitarist61]

That is a lovely image!