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Lobster, Clusters, Bubble & Gargoyle


PhotoGav

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There is so much going on in this wide field of view on the border of Cassiopeia and Cepheus that it is hard to know where to start! The largest object is The Lobster Claw Nebula (Sh2-157) in the upper right quadrant, with the small cluster, NGC 7510, above and to its left. The small bright nebula in the upper left is NGC 7538 - this little impish face kept on smilling at me throughout processing, so I have called it The Gargoyle. In the middle lower portion of the image is a very small looking Bubble Nebula (NGC 7635). Finally the open cluster M52 (NGC 7654) is glistening in the lower left corner.

Technical Details:

WO Star 71 with QSI 683-WSG and Baader filters

Ha = 23 x 1800s

R, G & B = 24 x 300s each

Total Integration Time = 17.5 hours

Lobster-HaRGB-11-Final.png

 

I have tried to tame the starfield which was almost overwhelming - this is a very starry corner of the sky! Overall I am pretty happy with this one, but as ever all comments are most welcome.

Here's hoping for clear skies soon...

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Very nice Gav, started a project on the Lobster Claw in NB, some really leery NB colour schemes on the internet :grin:

Never know what to do with rich starfields, either they overwhelm everything or make my background look muddy when tamed.

Dave

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Hello Mr Gav.  Great shot.  I agree with Davey-T about the slight muddiness.  The only thing I would add is that to me the background also looks like it has had just a shade too much NR - but what do I know?  (You are probably going to tell me there has be no NR of any sort!!)

Steve

 

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I agree with star control--I find that when I dim too many stars to the same pale dots, it looks like muddiness.  If you dim them too much, you are left with little black spots (holes), which obviously is not good.  There is a way to completely remove them, but that requires blurring the little black holes into the nebula which I never had the fortitude to learn.  A little star control goes along way.   The good thing about RGB data is the stars look naturally colored, which can help mitigate some of the muddiness.  Have some big ones, some middle sized ones, some small ones and some tiny ones, all in various colors and it will look 3D. I also agree with Steve about the noise control.  You may not have used any, but it looks like you used a bunch for what its worth.  But great image--one of my favorite locations in the sky.  

Rodd

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Thank you for your comments. Regarding noise reduction, I have applied just one iteration of Noel's Deep Space Noise Reduction, but at only 40% layer opacity, so basically next to nothing! I agree about the muddiness. I think that probably comes from the abundance of yellow stars. I was quite surprised that there weren't more blue stars when I was processing this. Could this be because the subs were relatively short? I wonder if 600s subs in RGB would generate more variation in colour?

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7 minutes ago, PhotoGav said:

Thank you for your comments. Regarding noise reduction, I have applied just one iteration of Noel's Deep Space Noise Reduction, but at only 40% layer opacity, so basically next to nothing! I agree about the muddiness. I think that probably comes from the abundance of yellow stars. I was quite surprised that there weren't more blue stars when I was processing this. Could this be because the subs were relatively short? I wonder if 600s subs in RGB would generate more variation in colour?

I find that RGB colors are pretty faint in stars for shorter subs (unless you have many, many).  600 sec would definitely yield more saturation in the long run.  If that does not do it, you can always bin the RGB 2x2 (resolution is not important in the RGB channels as the L and/or Ha will provide the details.  Also, isolate the stars (use a mask or use layers if you process in PS or GIMP and increase saturation just on the stars.  That may do it by itself with the shorter subs.

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The muddy colour in the background can be easily fixed in PS in the colour balance adjustment tool..... In shadows you can increase the blue / cyan a little and that will tackle that. I'd also consider the star colour a little in colour select and up the magenta a touch in the yellow as the stars look a little washed out.

All in all, I think that the nebula detail is there - Just some finishing tweaks that can improve things a little further :)

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Think you have all the advise you need there Gav - few tweaks will make this into a lovely image.  But we will have to debate the Gargoyle naming.  I think this candidate is right up there

2016-11-23_16-12-07.jpg

 That said my Rorschach blot assessment showed I am not all there!  Maybe I am the only one who sees it.

Back on topic though other than the 'mudiness' I do like the red and it works well over the frame.

Paddy

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Paddy - I think that qualifies for 'Hunchback Of Notre Dame' not 'Gargoyle'! Congratulations on this month's S@N Picture of the Month. I am happy to share the pages with you with my veiled cameo role!

Back to The Lobster and Friends...

Sara - I gave a tweak to the shadows using your suggested colour balance technique. I didn't want to go too far, so the effect is quite subtle, but definitely de-muddys the murky bits! Thank you for a great tip. I did try the selective colour tool on the stars as you also suggested, but that didn't seem to make much difference, so I ditched the idea!

Lobster-HaRGB-13-Final.png

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I think you have framed this image really well Gav and there is a lot to attract the eye.

As you yourself remarked and others have commented, the stars to me seem over subdued.  You have a good amount of data and I think there is some sparkle in the data that you need to lift out and give some more relief and brightness (brio?) to the image overall.  Controlling star fields yet giving them some element in the composition is a tricky balance.

I think the Ha shade of red is spot on for me and the second image has the better background balance.

I look forward to your next revision.

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Thank you Barry. Yes, the biggest problem with the Star71 is that it captures an awful lot of stars in its wide field of view - I guess the clue was in the title! All the images I have done with it so far have been brimming with stars, which makes teasing out the nebulosity a challenge. I will see what sparkle I can summon, without turning it into a picture of stars only!

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