NGC6559 et al from Ten Chain Hill

[RickS]

After having high hopes for last Saturday night after a lovely clear day, the clouds started to move in as I finished polar alignment. Despite the conditions I imaged anyway with Maxim beeping plaintively to complain of lost guide stars.

It cleared up around midnight and I awoke to find the data wasn't a complete disaster (thanks to ACP for looking after things while I got some shuteye). I'm not unhappy with the results although some may think my processing a little over the top. I'm still wondering if I went a bit too far myself :D

This was my first outing to dark skies with the Ceravolo 300 Astrograph and I'd have to call it a success since I came home with an image. With the weather we've been having in SE Qld that's no mean feat.

Scope: Ceravolo C300 @ f/4.9 = 1470mm FL, Atlas focuser
Mount: AP900
Camera: U16M
Filters: Astrodon E series Gen 2 LRGB
Guiding: Lodestar / MMOAG
Image scale: 1.26 arcsec/pixel
Exposures: 12x200s R, 12x300s G, 12x300s B, 36x300s Lum (6 hours)

Attached below are images of:
- the complete FOV
- NGC6559, IC4685, B302, B303
- IC1274

Larger versions are here:
http://rickstevenson.smugmug.com/Astro-Photography/2013-07/i-3ptPp3b/0/X3/NGC6559_v4_ps_med-X3.jpg
http://rickstevenson.smugmug.com/Astro-Photography/2013-07/i-xhPsKWw/0/X3/NGC6559_v4_ps_crop-X3.jpg
http://rickstevenson.smugmug.com/Astro-Photography/2013-07/i-BsWCTFZ/0/X3/IC1274_v4_ps_crop-X3.jpg

Constructive criticism appreciated.

Thanks,
Rick.

[Stevec35]

Hi Rick

A very nice looking image! I'm no expert in colour balance but there seems to be a bit too much cyan on my monitor though.

Cheers

Steve

[multiweb]

Love the details. Unreal image scale. Blue's and red's are white clipped though. Due for a redo. But still a great pic. :thumbsup:

[RickS]

Thanks, Steve & Marc. I used a new technique for processing the RGB that might need some tweaking. I will revisit the data tonight.

[Paul Haese]

One of my favourite areas on the night sky. What I like is your detail and smooth background. Perhaps a little too much cyan and the orange stars have a little too much cyan in my opinion. Other than that the image looks good. Besides you can always add more data to it and improve the colour.

[dvj]

I will offer that this scope in your hands has great potential! I had a chance to test a prototype a few years ago and was very impressed with its simple and elegant approach to design and collimation. Looking forward to more images.

[pmrid]

Rick, the difference between the first cut you did up here at 10Chain and the images you've posted is dramatic. I see how well you have brought out those fringing blues, the dark dust lanes and those intense bands of hydrogen - demonstrating why this region is on so many 'favourite' lists. Well done.

Peter

[RickS]

Thanks, Paul!



Thanks, John. It is a lovely piece of gear.



Thanks, Peter. I'm very happy with what I've squeezed out of the Luminance. Now I just need to get the colour right.

Cheers,
Rick.

[ozstronomer]

Nice result Rick, glad the clouds finally cleared to a good night.
That scope is really producing some excellent results

Geoff

[RickS]

Thanks, Geoff. Hope you got some nice data up at Crows Nest.

The white clipping of the blue and red that Marc noticed is proving interesting to figure out. It's mostly "caused" by the conversion to sRGB that I do at the end of my processing. I guess it's an out of gamut thing. Looks like I have some more work to do to figure out the best way to deal with this...

[RobF]

Wish I could have been there to see the gear in use.
Colours a little too technicolour for my taste Rick, but no doubting there's quality data in there. Wondeful shots for your efforts.

[RickS]

Thanks, Rob. I'm willing to admit the current version is a bit OTT :lol: I'm working to tone it down to almost tasteful levels.

[naskies]

Beautiful effort, Rick! The reds/pinks/purples/golds look fantastic... but the cyan is certainly new :question: That's some serious photon gathering kit ;) How is the Neumann Camera Tilting Unit working out?

[jjjnettie]

I simply love this region of the sky. Looking forward very much to seeing the repro. :)

[tilbrook@rbe.ne]

Wow Rick!

In your larger versions they are stunning, the cyan stars actually good too.
Love the resolution of you rig.

Cheers,

Justin.

[RickS]

Thanks for the feedback, everybody! Repro versions here:
http://rickstevenson.smugmug.com/Astro-Photography/2013-07/i-3ptPp3b/0/X3/NGC6559_v4_ps_med-X3.jpg
http://rickstevenson.smugmug.com/Astro-Photography/2013-07/i-xhPsKWw/0/X3/NGC6559_v4_ps_crop-X3.jpg
http://rickstevenson.smugmug.com/Astro-Photography/2013-07/i-BsWCTFZ/0/X3/IC1274_v4_ps_crop-X3.jpg

There were some interesting things happening in the processing of the colour data that I still need to figure out. I had to desaturate a couple of times (reduce CIE c* with curves) to prevent white clipping the red and blue channels when I converted to sRGB. Perhaps NGC6559 should be called the out-of-gamut nebula :lol:



Thanks, Dave. I'm hoping the gear will work even better on a good night! I haven't made much progress with the CTU. I managed to damage one of the adjustment screws using a ball head allan key at an odd angle so I had to wait for a replacement. It arrived yesterday.



Thanks, JJJ! Hope you like it! I'm very fond of this area as well. So much cool stuff. I'll probably try again at 2700mm when I get a chance.

Cheers,
Rick.

[Ross G]

Great looking photo Rick.

Amazing detail and colour.

What a beautiful object!

Ross.

[marc4darkskies]

You've got to be happy with that! Great detail and natural colour. Very nicely done Rick! :thumbsup:

Cheers, Marcus

[astronobob]

Unreal & spectacular capturing Rick :eyepop: Dig the colours, and amaizing details, a facinating area of sky, must make note of this target, I like it !
Great work & show :thumbsup:

[RickS]

Thanks, Ross.



Thank you, Marcus. The scope is working well. I just need to keep working on the processing skills!



Thanks, Bob. Would love to see what you can do with this target too!

[Elio]

A great image of a spectacular area :eyepop:
even more envious of your sky...and what a dream-setup! :thumbsup:

Elio

[atalas]

Rick,top stuff!

[RobF]

Ok. Well, that's moderately amazing now Rick ....;) :thumbsup:

[RickS]

Thanks Elio, Louie & Rob!

[strongmanmike]

Quite a good result Rick of a fascinating area, yes it does look nice and crisp :thumbsup:

Mike

[RickS]

Thanks, Mike!

When are we going to see some galaxies from your new AG12 set up? I'm looking forward to that.

[naskies]

Strange... did the colours look okay on screen? It sounds like a Relative Colorimetric rendering intent (clips out of gamut colours) was being used instead of Perceptual (this is usually preferred - compresses the image's gamut into the destination gamut).

http://www.cambridgeincolour.com/tutorials/color-space-conversion.htm

[strongmanmike]

Soon, soon...man, should see my list of potential objects :eyepop: :lol:...now if the weather will just cooperate :rolleyes:....

Mike

[RickS]

Yes, looked OK on the screen, Dave. I tried Perceptual first and then all three other options offered by PI ICCProfileTransformation (Saturation, Relative Colorimetric and Absolute Colorimetric). No luck with any of them. Might go back and have a further play and look more closely at the numbers...

[whzzz28]

Looks like your night out there was good one!
Might just be me (or my screen) but the blue hues look interesting, as if washed out a bit.

Sadly I got called up to work, on a Saturday, at 3pm when i was packing the car... :mad2:
Maybe next time.

[RickS]

Didn't seem like a good night at the time with clouds coming and going! As usual, I struggled a bit with the colour. It probably could still be improved...

Cheers,
Rick.

[Shiraz]

glorious image Rick. excellent colour and detail.
Be interested in what you find re minor star colour issue.
regards Ray

[RickS]

Thanks, Ray. Will let you know if I find out anything interesting.

[TrevorW]

Nice !!

[jase]

Rick, are you getting these colours straight out of a colour combine and if so what are your colour weightings you are using? Colours appear rather washed. RGB is an additive colour palette thus as data is stretched, saturation also need to be increased incrementally. My favourite to bring back rich colour is a reasonably heavy stretched DDP RGB layer with ample blurring to curb colour noise, the use this layer as a soft light blend in photoshop. You may need to dial back the opacity a little as it will darken the image somewhat but that's the reason why it needs to be heavily stretched (just watch out for clipping).

[RickS]

Thanks, Trevor.



Jase: I tried a variety of RGB combinations using eXcalibrator weights (which I liked the best) and PI BackgroundNeutralization + ColorCalibration. I don't have any trouble increasing the saturation in PI but the bluish stars have a tendency to turn a garish cyan colour. I suspect there was something odd going on when I converted to sRGB. I'm going to spend a bit more time playing with the colour data now that we're having some rainy nights :lol: Thanks for the suggestions. I might have a play in Photoshop as well and see what I can do.