M101 4.5 hours RGB

[Padraic M]

This is the results of 4.5 hours of OSC imaging from dark skies (B2) last night. The night started with really clear air and the darkest I've seen for some time. It did fog up a little in the early morning.

This is a new rig for me - SW 150PDS Newt and ASI533MC Pro camera with Baader UV/IR Cut filter installed. I could see M101 already in the 8-second platesolve images; the first few subs were 120s but looked so clean that I bumped up to 5 minutes for the rest of the sequence.

This is almost uncalibrated - 5min darks are cooking as we speak, and my flats are over-correcting for some reason so I just used some old flats I had lying around and the APP Correct Vignetting tool which did a pretty good job.

I also have a new processing workflow, using APP for stacking, Siril for background extraction, photometric colour calibration and stretching, and adding the final touches in Gimp.

When I have a full set of calibration frames I may be able to improve on this - I sense that there is some more detail to bring out in the outer spiral arms. I might also try to add some old Ha data from last year.

 

[paul]

A very nice result, good colour and detail there👍

[Padraic M]

Seriously though, when you have to deal with this piece of Musk dung, it would make you question why you bother 🤔

This is my top SNR sub too! Had to exclude it as APP is not doing a great job of rejecting them.

[Dmack1]

Thats a nice image, Lots of structure and well defined arms.

 

[Padraic M]

Here's the final version with proper calibration applied; sigma stacking to remove the sat trails, and using just the best 75% of subs. This is 39x300s subs for a total of 3hrs 15mins.

 

SW 150PDS, ASI533MC Pro @ -15c/gain 100/offset 21.

HEQ5 Pro mount, TS-Optics 50mm guide scope, ASI120MM Mini guide cam.

Captured with NINA and PHD2.

Processed with APP, Siril and Gimp.

 

[TerryMcK]

Great image Padraic despite incursions from satellites.