M83 Southern Pinwheel Galaxy

[Startrek (Martin)]

Here’s another image captured last week from my NexDome Obs on the South Coast
Conditions were average which showed in the guiding and slightly bloated stars but clear skies on both nights
After going through all the data I managed to put together about 5 hours over the 2 nights
10” f5 KH Carbon fibre Newt
EQ8-R pro mount
ZWO2600MC

Astrobin link below …..

https://www.astrobin.com/fesvja/

Synthetic Luminance version ,original frame and crop
Colour version , original frame and crop

Comments always welcome
Thanks
Martin

[TrevorW]

Nice although probably a bit too purple for my taste

[Mickoid (Michael)]

Martin, I'll have ro agree with Trevor on this one. Too much saturation in the spiral arms, pull it back to a more moderate level and I think it will look a lot better. I'd still be happy getting a result like that. Interestingly, your shot of M83 posted several days ago with your 6 inch Newt has captured almost as much detail as the 10 inch and from a much light polluted location. This can only emphasise the fact that seeing and transparency rule the result of any capture, regardless of location. It can get pretty misty down there on the South Coast. Conditions have to be perfect. If there's a strong easterly blowing, that seaspray can reach inland a fair way from the beach. Is your Obs close to the sea?

[Startrek (Martin)]

Totally agree Trevor and Mick,
Definitely not my best colour processing, yes too much saturation and not enough green bias
Yes on the South Coast I’m 200m from the beach but up at 50m above sea level on the lee side of a hill with 360deg clear views from 25deg up . Seeing wasn’t the best over those two nights.
The big difference between Sydney’s M83 image and South Coast Obs M83 image is the noise floor, in Sydney the noise is terrible which does hamper fine detail and leaves you with fine mottle
The Obs M83 was virtually noise free ( have a look at the Synthetic Luminance version rather than the colour version )
I think if I work on the colour , the M83 Obs image will be a much better image than Sydney’s M83

Thanks for the critique

Cheers
Martin

[alpal]

Hi Martin,
a great image.

I checked it out in Photoshop.
It looks better if the image is converted to Lab Mode and
then only the Blue is reduced a bit.
Also - the center of many stars are dimmer than further out.
I don't know how you did that?



cheers
Allan

[Startrek (Martin)]

Originally Posted by alpal

Hi Martin,
a great image.

I checked it out in Photoshop.
It looks better if the image is converted to Lab Mode and
then only the Blue is reduced a bit.
Also - the center of many stars are dimmer than further out.
I don't know how you did that?



cheers
Allan

Thanks Allan,
I also checked the image on my other desktop with Windows 10 Photo and the colour is different from my Astro computer , it’s more of a deeper blue.
In regard to the stars , did you mean brighter in the central core not dimmer ?

Cheers
Martin

[alpal]

Thanks Allan,
I also checked the image on my other desktop with Windows 10 Photo and the colour is different from my Astro computer , it’s more of a deeper blue.
In regard to the stars , did you mean brighter in the central core not dimmer ?

Cheers
Martin

No - darker at the center of many bright stars.
see attached a zoomed in version.


cheers
Allan

[Startrek (Martin)]

Originally Posted by alpal

No - darker at the center of many bright stars.
see attached a zoomed in version.


cheers
Allan

Oh yes , caused by poor selection of sample stars in the Apodization mask when using Spatially Variant Point Spread Function Deconvolution in Startools. Plus I tend to push this algorithm too hard to get more “de blur” out of the image. SV Decon uses the stellar profiles of sampled stars across the image to assess and apply Deconvolution in according to spatial variances, unlike traditional Deconvolution where it apply one set of algorithms across the image as a hole.
Still learning this unique tool
Good pick up though

Cheers
Martin

[Dave882 (David)]

Nice and clean and good detail Martin. Keep ‘em coming!!

[Startrek (Martin)]

Originally Posted by Dave882

Nice and clean and good detail Martin. Keep ‘em coming!!

Thanks Dave,
I agree with everyone, colour is this image needs some work, but the detail is very satisfying
A few more to process from my stint in the Dome

Cheers
Martin