The Running Chicken Nebula (IC 2944) in Centaurus (WIP)

[Octane]

I've made progress on my recent project.

I'm quite happy with the way this is turning out.

I've captured the LRGB stars to replace the purple mess in this image, but, I'm waiting to capture my blue flat frames (hopefully tomorrow morning) then I can combine the LRGB stars into this and finish it off.

This is the Lambda Centauri Nebula (IC 2944), colloquially referred to as the Running Chicken Nebula, flanked on the left by the beautiful open cluster called the Pearl Cluster (NGC 3766).

This is my longest cumulative exposure to date. I captured over 80 hours of data but whittled it down to the best 60 hours. 20 hours of hydrogen alpha, 20 hours of oxygen III and 20 hours of sulphur II. Each exposure was 30 minutes long. This works out to 120 individual exposures.

This palette is OIII, SII and hydrogen alpha mapped to red, green and blue respectively. The traditional SHO mapping looked garish.

I hope you like what I've done thus far.

SBIG STL-11000M, Takahashi FSQ-106N, Losmandy G-11 Gemini
120 x 1800.0s f/5.0 at 530.0mm -20 degrees Celsius

50% resolution available here (http://octane2.ddns.net:81/astro/ic2944.html).

I should add that this is straight out of Pixinsight. I haven't taken it to Photoshop yet.

Comments, critique, lynching, etc., welcome.

Thank you for looking.

H

[markas]

Humayun,

I won't be leading the lynch mob - This is an interesting and unusual palette which I think works well on the subject.

Mark

[strongmanmike]

Wheel... the colour is gunna polarise for sure... but after a few looks ,hey, I don't mind it and you can see the contribution of three channels (kinda...), looks rather icy huh? :thumbsup: However, the overall clarity and the handling of the dynamic range (even without the blue flats and RGB stars) is undeniably rather well done Humayun and kudos on the time and effort involved :thumbsup:

Seriously, if people can't see the running chicken (running to the left, flapping wings outstretched, neck stuck slightly forward complete with beak jutting forward and even a V shaped comb on top of her head) in this image :eyepop:...man, well, they must just have obstructed eye to brain pathways :shrug: :lol:

Mike

[RickS]

Very cool, H. Looks like an Anglerfish to me :lol: My only suggestion is that a JPM tone mapping approach might be worth considering. I think it gives a much cleaner look and a lot more latitude to play with the colours.

Cheers,
Rick.

[strongmanmike]

Bah!...You need a new brain Rick :rolleyes: :lol:

[alan meehan]

very nice H well worth the effort one of the best chicken I have seen
AL

[RickS]

Abbey Normal? https://www.youtube.com/watch?v=yH97lImrr0Q

[DJScotty]

That's an awesome effort H. The RGB stars will look great I think...

[gaseous]

This is the first proper photo I've seen of this object, which was quite "blink and you'll miss it" visually when I was looking a few weeks ago, but this is quite striking. Looks more like a 'run over chicken', but the result is spectacular.

[strongmanmike]

Aaah Mel Brookes :prey2:

Nothing Abi Normal about your image H :thumbsup:

[cometcatcher]

That's an awesome image H. I like the palette.

Personally I think it looks more like the FSM than a chicken though. ;)

[marc4darkskies]

Very interesting palette there H! :confuse3: Not a big fan I admit - I prefer the traditional SHO. But it's a very compelling image nonetheless ... even though you whittled it down to mere 60 hours. :scared2:

Have you white clipped your blue (Ha) channel (?)

[Andy01]

I'm enjoying ghe composition, but the colour palette leaves me cold.
Looks a bit too UV nightclub-ish to me and appears very bi-colour, but hey, good on you for trying something new in NB!
Amazing deep detail in the Ha regions too, well done :)

[Atmos]

Nice and deep H, kinda see the chicken, a flapping one but not a running one!

[Octane]

Thanks, Mark. :)



Cheers, Mike.

Looking forward to adding the LRGB stars and perhaps trying a different palette. It's not set in stone. :)



Rick,

I'll have a look at the JPM tekniq. The SHO palette was all green. I'm not sure what's going on. I linear fit everything to OIII as it had the broadest histogram. Perhaps I should have fit everything to hydrogen alpha? Any ideas as to what could be causing the massively green bias?



Thanks, Al. :D



Thanks, Scott. :)



Cheers, guys.

H

[Octane]

Patrick,

Many thanks for your thoughts. :)



Kevin,

Yay, that's another vote for the palette. As mentioned to Mike, it's not set in stone and could change. It looked different and the contasting colours appealed to me. :)



Marc,

It is an interesting one, isn't it. Rather electric? I haven't seen any other OSH images of this so thought I'd give it a go.

And, yes, the blue is clipped. I was in a hurry to finish processing before my wife came home (lol) and saved it in a rush. It's still open on the Mac waiting for me to finish it off!

As for the 60 hours; it has made a massive difference -- I haven't run any noise reduction processing/routines on any of the channels. There simply isn't any need to. I'll put the 100% resolution up once it's complete and people can pixel peep it to death then. :D



Andy,

Mate, I took a leaf out of your book and went beyond electric. :D

The straight SHO combination is rather green. I'm guessing it's very strong in hydrogen, and, that's why. I'll try mixing the first two channels and see what happens, then. This palette isn't set in stone, but, I kind of like it. It's like cosmic fairy floss.



Colin,

Cheers; glad you like it. :)



Thanks, all.

H

[RickS]

H,

The choice of LinearFit reference can make a difference but I haven't found a way to predict the best choice. I usually just pick one at random and work with the result.

A green bias is very common even after a LinearFit. DBE or BackgroundNeutralization will go a way towards fixing it. After a stretch I normally use the ColorMask script (not part of the standard distribution yet but you can get it on the PI forum or ask me for a copy) to do something equivalent to the Bob Franke method for PS (http://bf-astro.com/hubblep.htm). Colour masking is actually more powerful than PS selective color because you can apply a range of tools to the masked image.

Removing the stars from the colour image (keep them in the synthetic luminance) works really well too. That's the core thing I took from JPM's tone mapping. It gets rid of those horrid magenta stars :) It also allows you to do heavy noise reduction and a much bigger stretch on the weaker NB filters to get a lot more latitude with colour adjustment.

Cheers,
Rick.

[topheart]

Hi Humayun,
I really like the image. Well done!

The colour scheme creates a unique feel to the image which appeals to me.

An interesting discussion also ...thanks!
Cheers,
Tim

[el_draco]

What a fabulous short. Looks almost 3D. Just beautiful :thumbsup:

[Placidus]

I displayed your excellent image to SHO because that's what I'm familiar with. It looks great. Regardless of mapping, there is exquisite depth and detail. Good judgement call on the balance between the faintest and brightest structures, leaving excellent mid-tone contrast. Lovely composition too. Fantastic work. :thumbsup::thumbsup::thumbsup:

Best,
Mike

[Octane]

Rick,

I ran BackgroundNeutralization, balanced colour and DBE on my combined image. Unlocking the STF yielded the minutest change in star colour, so, my colour balance should have been pretty spot on.

What I might try doing is a DBE on each channel before running LinearFit. I understand that it is often best to LinearFit to the channel with the lowest signal, otherwise you run the risk of increasing noise if trying to fit low signal channels to high signal ones. Makes sense. So, this time, I will try to fit to SII instead of OIII. At any rate, it can't hurt to try.

If you can email me a copy of your script to my email, I'd appreciate it. I'll send you a message on spacebook.

Many thanks for your detailed reply.



Tim,

Thanks, sir. Glad it appeals to you. :)



Rom,

Thanks, mate. Can't wait to post the final rendition soon!




Mike,

Thank you, very much! I paid a great deal of attention to the centre/brightest areas (after 60 hours of exposure, it was quite bright and was very conducive to bringing out the fainter structures by bringing the midtones down).



Thank you, one and all. :)

H

[RickS]

Hi H,

Sounds reasonable but the weakest channel still needs to be stretched to match the others for a good colour balance so the noise is going to get increased anyway. That's another thing addressed in JPM's tone mapping technique - you can do a heavy noise reduction on the weak channels.



Will do! There is an example of its use here: https://pixinsight.com/forum/index.php?topic=7751.0

Cheers,
Rick.

[Star Catcher]

Well that is a different looking palette! Lovely details in the image. I admire the effort you put into this image. Obviously good enough tracking to do the job :)
Ted

[Octane]

Thanks again, Rick. :)

And, thanks, Ted!

With Rick's awesome ColorMask script and altering the amount of hydrogen alpha, I have come to process a normal SHO palette and it looks pretty good to me. I might make an alternate version, in this palette, too.

Still trying to find time to do the LRGB combine for the stars!

H

[RickS]

No problem, H. Look forward to the latest results!