M81 - two nights of data and some Wild Turkey

[discardedastro]

OK, so, this was entirely processed under the influence of Wild Turkey (only fitting given the season) Old Fashioned, so may be of variable quality! I think I did everything right in PI, but who knows. Most of the capture time was also spent somewhat inebriated. Christmas on your own is super fun!

Taken from two nights of data this month, for a total 65x120s L and about 50x120s RGB.

All taken on my usual rig; 200PDS on EQ6-R Pro, Baader Steeltrak w/ Sesto Senso for focusing, TeleVue Paracorr, ZWO OAG, ZWO Mini EFW w/ Baader LRGB filters, ASI174MM guide cam, ASI183MM-PRO imaging cam. Astrozap dew shield on the scope and Lacerta dew heater on the Paracorr. KStars and Ekos for acquisition. First night was calmer with better seeing, second night was a bit more windy so I discarded more frames due to wind. About 80% of frames ended up being used, weighted accordingly.

Processing was reasonably straightforward and entirely within PixInsight manual end-to-end; calibrated w/ flat+dark, subframe selectored to ditch the frames most badly affected by wind, cosmetically corrected against dark and 6-sigma auto, stacked (with linear fitting and standard normalization, generally, but L stacked with 256-pixel Local Normalization), deconvolved (40 rounds of RL-R w/ 4 wavelet layers) using a dynamic fit PSF and local deringing, cropped, DBE'd, RGB was linearfitted before channel combination. L was MureDenoised, masks were used for MLT denoise on all background data before final stretching and LRGBCombination. Masked TGVDenoise to finish and some colour saturation to bump things up a bit. Lastly, photometric colour calibration and automatic background extraction to lose the last gradients.

Not by any means my best but a pleasing result nonetheless I think!

Edited December 27, 2020 by discardedastro

[tooth_dr]

Wow! Looks like really good data! Stunner.

[discardedastro]

My "best frame" from this attached, in FITS and JPEG. Quite happy with how the Paracorr is performing, though still need to fix a tiny bit of tilt (adapter on the way!)

M_81_Light_Lum_120_secs_2020-12-24T23-05-11_034_c_cc_a.fit

[geeklee]

Very nice @discardedastro That's come out very well. Some nice Ha regions showing through too.

The single sub above looks great. 

To my eye, the core area outwards looks a little green, something SCNR (green) might provide a quick fix for if so inclined. Could just be my phone view though. Looks great anyway 🙂

8 hours ago, discardedastro said:

Lastly, photometric colour calibration and automatic background extraction to lose the last gradients.

I haven't seen this written much, performing these two steps last on non-linear data. Do you find this easier or produces better results for you?

[discardedastro]

3 hours ago, geeklee said:

Very nice @discardedastro That's come out very well. Some nice Ha regions showing through too.

The single sub above looks great. 

To my eye, the core area outwards looks a little green, something SCNR (green) might provide a quick fix for if so inclined. Could just be my phone view though. Looks great anyway 🙂

I haven't seen this written much, performing these two steps last on non-linear data. Do you find this easier or produces better results for you?

I'll be honest - I forgot to do it till the end! I normally do it immediately post-DBE on my RGB master prior to delinearisation for LRGBCombination. Having said that, it worked just fine on non-linear data.

Looking with slightly less inebriated eyes, you're right on the green cast - and an SCNR has indeed tidied that up.

[geeklee]

14 hours ago, discardedastro said:

OK, so, this was entirely processed under the influence of Wild Turkey

 

2 hours ago, discardedastro said:

I'll be honest - I forgot to do it till the end!

2 hours ago, discardedastro said:

Looking with slightly less inebriated eyes,

😁 I think I'd forgotten the underlying theme of the evening when I got to looking at the image😁

Lovely image 👍