M81 M82, 8.1 hours Jan - Mar 2023

[The Thing]

I've had a lot of exasperation with this one, see my earlier post
M81 M82 Starless Image Help!.

I think I've done a reasonable job but have lost a lot of the IFN despite lots of masking etc.

122x4mins, Gain 120, Offset 4, Temp -5c
Image date, time and location: Jan 22 and Mar 14 2023,  Manche, France
Telescope aperture and focal ratio: TS1506UNC 600mm f4, TSGPU Coma Corrector
Camera and filters used: ZWO ASI294MC Pro, Svbony UVIR
Processing applied: Pixinsight, Affinity Photo 2

Click image for full size version.

[Roberto]

Very good!  Some IFN floating around also 

[Carole]

It's a good image, IFN is difficult to bring out but can definitely see some.

Carole

[Ivor]

Really nice image, it would be interesting to compare PI workflow. In case you haven't noticed you have a small green artifact in the centre of M82.

[The Thing]

Thanks Ivor. I did notice, damn them aliens.

My workflow is basically:
1) PixInsight WBPP (Weighted Batch Preprocessing - calibration and stacking process wizard) using defaults, darks, flats, darkflats, no bias. If I use my QHY294 rather than my ASI294 it has access to overscan areas on the subs so I use them as well. Auto crop and 1x drizzle with 0.9 drop shrink (may try something different next time), Quality preset set to highest, it makes time for another cup of tea.
2) EZDeconvolution with a souped up generated starmask and around 100 iteration with Pixel math of 5 iterations.
3) EZDenoise with defaults and ~1200 iterations depending
4) Then this image was split with Starnet2 process which made a really good job
5) GSH General Hyperbolic Stretch of the RGB with a colour stretch (there are some good tutorials out there) of the Starless image
6) EZStarReduction the StarMask (bad name!) image, Adam Block method
7) Archsinh stretching of the StarMask
Export both bits as TIF 32bit floating and import into Affinity Photo 2
9) Tweak both images with Clarity filter, Curves, Saturation, etc. etc. with masking as needed.
10) Combine both images and fine tune looking out for green artefacts (Doh!)
11) Export as JPEG

[JohnH]

it makes time for another cup of tea.

WBPP is fantastic. I am glad that I watched some Adam Block videos which persuaded me to use it. The only downside is that I have read "War and Peace" so many times while waiting for it to complete that the pages are falling out.

Thanks for listing your workflow - it is very useful.

JohnH

[MarkS]

That's a wonderful result.  Really well done!  Holmberg IX and the IFN are both showing.

Mark

[garrick]

Really nice image. Good colours.

Clear skies,

GW