M13 - Great Cluster in Hercules

[Stub Mandrel]

In my previous post I observed that my data for M13 could do with a bit more processing to make it 'sparkle' more.

I adjusted the original RGB image as a colour layer, slightly increasing the saturation and softening it a bit as some yellow stars had become a bit posterised on close inspection.

I went back to the original data and reprocess it it with a lot more effort on brining out faint stars  while not blowing out the core. Then I applied some very gentle lucy-richardson deconvolution, basically kernel size and kurtosis set on 1 except strength at just 0.7. This was enough to make the stars in the core more prominent and lift up the fainter outer ones.

Although this was now a nice RGB image, the colour wasn't as good as the original so I combined them with the new image as a 92% luminance layer.

Finally I slightly blurred the cores of the two big stars to tone them down a touch.

[Saganite]

What is there not to love about M13, just glorious isn't it, and that's a lovely image. 

 

Edited May 25, 2020 by Saganite

[Skipper Billy]

Loving it!

 

[Whistlin Bob]

Just a wonderful image Neil

[Stub Mandrel]

I'm grateful for all the positive feedback on this image, but I wasn't happy with the star shapes, the middle sized stars had a sort of 'point' underneath. I ruthlessly went through all the subs, removing a few where the dec had jumped giving stretched or slightly doubled stars, and re-stacked the best of the RGB together as a Lum layer. I also notoiced the original didn't use sigma stacking so at least one satellite trail was visible. It was challenging as removing too many subs lost the faint outer stars which make this image special. getting it right was tough but kept these stars and got rid of some noise but mostly improved star shapes, especially on the medium sized stars. I also slightly increased the saturation on the yellow stars to make them less biege. For some reason, this data don't blow out as easily either, so I didn't need to play with the core or bright stars yet it looks a bit sparklier.

So, I think Version 2 is a tad better again:

[MartinB]

M13 is one of those targets you can never be happy with.  Treat it gently and there is so much you can't see.  Try to pull out more of the cluster and the core starts to loose its definition.  You've done a fine job here and seem to have got the balance just right.  Now is the time to stop tweaking!

[cuivenion]

On 31/05/2020 at 19:55, Stub Mandrel said:

I'm grateful for all the positive feedback on this image, but I wasn't happy with the star shapes, the middle sized stars had a sort of 'point' underneath. I ruthlessly went through all the subs, removing a few where the dec had jumped giving stretched or slightly doubled stars, and re-stacked the best of the RGB together as a Lum layer. I also notoiced the original didn't use sigma stacking so at least one satellite trail was visible. It was challenging as removing too many subs lost the faint outer stars which make this image special. getting it right was tough but kept these stars and got rid of some noise but mostly improved star shapes, especially on the medium sized stars. I also slightly increased the saturation on the yellow stars to make them less biege. For some reason, this data don't blow out as easily either, so I didn't need to play with the core or bright stars yet it looks a bit sparklier.

So, I think Version 2 is a tad better again:

 

Looks good to me!