Yet another M31
although working with unsupported filetypes is a pain, I got pretty good results by converting to tiff with dcraw (following options : dcraw -q 3 -4 -t 0 -T ). This is 3 hours of integration time in 120 sec subs with 25 darks and 30 flats.
Camera: Sony A7rII
OTA: Canon 300/2.8 L USM (1st gen without IS) and Canon 2x TC III adapted with Metabones IV
Mount: Skywatcher Star Adventurer guided with Lacerta MGen II and an Orion Mini Guide Scope
Site: Bortle ~3
Seeing: initially good but decreasing in the last hour
Calibration of darks and flats with Sigma clipping 3 and 1 iteration
Integration with Sigma clipping 3 and 3 iterations, equal weights
The lens has some ca when paired with the 2x tc and so I first had to remove this defect in LR before running star color correction but even with that done the colors needed a lot of tweaking. I am already collecting HA data in order to bring out the star forming pockets.
A higher resolution version of the image can be found here : google drive link
Thanks for watching and reading. CS