Celestial hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  Bode's galaxy  ·  Bode's nebulae  ·  M 81  ·  NGC 3031
M81, iva
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M81

M81, iva
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M81

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Description

Back to imaging after a long pause, three wonderful clear sky nights in a row, I couldn't pass even if it was full moon and a galaxy in LRGB wasn't the ideal target!

Took a lot of subs in L but there wasn't that much difference in SNR between ~80 and ~230 subs stacking.

Couldn't get the stars' colours right and I had to raise the black point a bit too much to get rid of of subtle but very noticeable background gradient.

Now for the good news, I'm happy about the result of Multiscale Linear Transform noise reduction in PixInsight for the linear image, much less ringing.

I preferred TGVDenoise in the past but now I'm using it only for the stretched image.

Also tried to use multiple masks, one for the full galaxy and another smaller one for the core to highlight the darker lanes using Local Histogram Transformation in combination with HDR Multiscale Transform.

Enjoy!

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M81, iva