M104 Sombrero Galaxy from my NexDome

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Startrek
Posts: 351
Joined: Mon Dec 30, 2019 3:49 am

M104 Sombrero Galaxy from my NexDome

Post by Startrek »

Had a great week down at my rural coastal retreat using my NexDome Obs where I had 4 clear nights with no moon around. Seeing was average but who’s complaining.
Captured 4 objects in total , one of them being M104 Sombrero Galaxy
Decided on 2 minute subs but in hindsight should have pushed 3 or 4 minute at my low read noise Gain setting of 101 to expose a bit more find detail.

Also I think the image could be a tad brighter too
I thought about using Super Structure Brightness preset but found in the past it does hinder really fine detail ( more suitable for large emission nebula not dim galaxies)

Astrobin link here for more details ….
https://www.astrobin.com/3cofwx/


Comments welcome
Thanks
Martin
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Stefan B
Posts: 422
Joined: Sat Oct 31, 2020 8:59 pm

Re: M104 Sombrero Galaxy from my NexDome

Post by Stefan B »

Really an impressive image, Martin! Looks so easy and subtle although it's such a small and difficult target; at least as far as I can judge. I tried it two or three years ago. But it doesn't exceed 30° degrees, so... Anyway, that you got so much detail in the dust lane is insane. Again, really impressive.

Only thing I noticed is the galaxy core which looks a bit burned out. Did you include the ROI during stretching? Or was this the result of deconvolution? So reallocating the dynamic might help?

Regards
Stefan
Startrek
Posts: 351
Joined: Mon Dec 30, 2019 3:49 am

Re: M104 Sombrero Galaxy from my NexDome

Post by Startrek »

Hi Stefan,
Thanks for the flattering comments
A 10” newtonian and dark skies gives you so much more opportunity in imaging , I know , as I image from both ends of the spectrum ( Bortle 8 and Bortle 3 )
Initially I wasn’t too worried about the core , but good point as it does look detract from the overall image
I always use AutoDev with ROI and adjust all settings to taste like ignore fine detail , Gamma , linearity etc….
Im sure SV Decon was the culprit as it deconvolved that bright core thinking it was a star , even though I had it masked
Anyway very pleased with the final image for only a few hours on quite a dim Galaxy

Clear Skies
Martin
Mike in Rancho
Posts: 1141
Joined: Sun Jun 20, 2021 10:05 pm
Location: Alta Loma, CA

Re: M104 Sombrero Galaxy from my NexDome

Post by Mike in Rancho »

Super cool! :D

Yes deep in there is a little bright knot, and maybe ended up with some ringing about it? Have to get the nose up close to the screen to tell, though.

A few weeks back, I think at the last page of the BXT discussion, Ivo provided some answers to the "star"-creation-in-galaxy-cores issue, as well as the same suggestion to add a wee bit of dynamic range in SVD if needed.

An alternative quick fix, at least if one is sure you have an artifact or blob of full pixel saturation, would just be a quick mask blur in layer using a tiny bit of kernel radius.

Also, if I recall correctly, starting with SVD in 1.8 the masking (modifiable back then!) wasn't a go/no-go for deconvolution as in 1.7, but would act as an assist for deringing. As such, a custom touch-up of that mask might help out the deringing even more.
Startrek
Posts: 351
Joined: Mon Dec 30, 2019 3:49 am

Re: M104 Sombrero Galaxy from my NexDome

Post by Startrek »

Thanks Mike
Looking at it again , I kinda like the core the way it is , gives the image some character
Really enjoying getting down to my Obs under dark skies with my 10” Newt

Cheers
Martin
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