The Cauldron - (IC 2944 in NB) UPDATED 3/3/15

[Andy01 (Andy)]

Hi everyone,

Latest effort from last weekend away at LMDSS, Heathcote Victoria.
Lovely dark skies all night. Added a little more NB data from home as well.

5 hrs HA 900 sec subs 5nm Astrodon
3.5 Hrs O3 900 sec subs 5nm Astrodon
3.5 Hrs S2 900 sec subs 5 nm Astrodon
5x2 min RGB subs ea for the stars

Hubble palate with a few twists, I was inspired by the masters Pugh, Rat156, Bassnut & others to try this, but with the Astro Anarchy style tone mapping

Kinda reminds me of the Olympic torch flames cauldron from the opening ceremonies. Much more interesting than a running chicken imo

(UPDATED MARCH #3rd) New High Res here.. http://www.astrobin.com/157196/B/ (Worked on star shapes and colours in Startools.

Hope you like it, all comments, suggestions and improvements welcome - (but maybe no channel splitting ok!)

Andy

[Ryderscope (Rodney)]

Fantastic image Andy. Great colour palate and very nice detail.
I can see all sorts of shapes in the swirls of colour.
Thanks for posting.

[Stevec35 (Steve)]

Nicely done Andy. Vibrant and detailed.

Cheers

Steve

[alpal]

Nice work Andy,
& no need to split those channels - so don't worry.

cheers
Allan

[Eden (Brett)]

Excellent image, Andy. Very impressive color and detail!

[Ross G]

Great looking photo Andy.

I love the detail and composition.

Ross.

[Paul Haese]

The full resolution shows fairly good detail, and overall a nice colour palette but I think you might want to remove the cyan present in the blue stars and some of the background.

I think it might also be worth looking at the cause of the misshapen stars. It appears you have a fair amount of tilt occurring in the bottom right hand corner with it becoming less on each adjacent corner and nearly none at all in the top left hand corner. This must be something to do with the connections between the camera and flattener. I am assuming that the flattener is screw threaded to the telescope? Sorting that problem will certainly make a huge difference to how the image looks.

[strongmanmike (Michael)]

Nice view of the chickens bum Andy, that FOV looks great for this object too, like a big cave, don't mind the colours either. The stars bottom right do look like tilt and would be worth an investigation but overall a pleasing image for sure and no paint by numbers look this time either

Mike

[multiweb (Marc)]

Really well done Andy. I like the colors and contrast. That's a cool object to image in tri-color NB.

[Andy01 (Andy)]

Originally Posted by Ryderscope

Fantastic image Andy. Great colour palate and very nice detail.
I can see all sorts of shapes in the swirls of colour.
Thanks for posting.

Thanks Ryderscope, glad you liked it appreciate your comments

Originally Posted by Stevec35

Nicely done Andy. Vibrant and detailed.

Cheers

Steve

Thanks for taking the time to comment Steve, glad you like it too

Originally Posted by alpal

Nice work Andy,
& no need to split those channels - so don't worry.

cheers
Allan

He He He, thanks Allan - now tell me what you really think! Seriously, I value your input, cheers Andy

Originally Posted by Eden

Excellent image, Andy. Very impressive color and detail!

Thanks Eden - Appreciate the positive feedback

Originally Posted by Ross G

Great looking photo Andy.

I love the detail and composition.

Ross.

Thanks for taking the time to comment Ross. cheers!

Originally Posted by Paul Haese

The full resolution shows fairly good detail, and overall a nice colour palette but I think you might want to remove the cyan present in the blue stars and some of the background.

I think it might also be worth looking at the cause of the misshapen stars. It appears you have a fair amount of tilt occurring in the bottom right hand corner with it becoming less on each adjacent corner and nearly none at all in the top left hand corner. This must be something to do with the connections between the camera and flattener. I am assuming that the flattener is screw threaded to the telescope? Sorting that problem will certainly make a huge difference to how the image looks.

Thanks for chiming in Paul, appreciate your taking the time to pass on some good feedback and tips. I used Noel Carboni's astro actions - increase star colours a couple of times - maybe I've overdone it there.

I took the stars in RGB at the Dark sky site too, and it seems they are a bit blown out compared to what I usually get from my light polluted suburban home in Melbourne. Looks like I overcompensated with the actions. I used the same 2 min subs so maybe next time I'll cut the exp time back when I'm at LMDSS - there's so many more stars there!

The flattener connection is screw threaded to the camera, but not screw threaded to the 'scope so it's not ideal - it's two or three pressure screws there so maybe that's something I can look into.

What do other people do in this case?

Originally Posted by strongmanmike

Nice view of the chickens bum Andy, that FOV looks great for this object too, like a big cave, don't mind the colours either. The stars bottom right do look like tilt and would be worth an investigation but overall a pleasing image for sure and no paint by numbers look this time either

Mike

Thanks Mike - always learning from you - will need to research the flattener/scope cnxn as mentioned above. Yes, lesson learned - I used a more gentle hand in post this time around

Originally Posted by multiweb

Really well done Andy. I like the colors and contrast. That's a cool object to image in tri-color NB.

Hey thanks Marc, appreciate your input again
I'm by no means the first person to render this object this way, but it was fun to see the NB results - especially compared to what I got from my old OSC. Narrowband rocks!

It's also interesting to compare the results from Ha NB imaging at home and at at a dark sky site on this same object. The difference is marked - more stars, brighter contrast, more whispy bits etc. Might post them up later as well.

Cheers
Andy

[tilbrook@rbe.ne (Justin Tilbrook)]

Beautiful image Andy!

Rich and detailed can't ask for more.

Cheers,

Justin.

[alpal]

Andy,

He He He, thanks Allan - now tell me what you really think! Seriously, I value your input, cheers Andy

Hi Andy,
Your pictures are lovely.
When I look at the histograms I'm not sure that they are balanced & also
are stretched for the maximum compression to reveal all the delicate
changes in amplitude from the dimmest to the brightest signal.
Are you stretching very carefully in 32 bits from the original FITS stacks?

When I look at the details - see attached -
I see a non balanced histogram with very steep left hand sides -
almost vertical on the left & the Green at a different starting point compared to Blue & Red.
It looks like it's not stretched carefully at the lowest brightness levels.


cheers
Allan

[Leonardo70 (Leonardo Orazi)]

Very nice Andy

All the best,
Leo

[RickS (Rick)]

An interesting rendition, Andy.

[Waxing_Gibbous (Peter)]

Images like this are why I chucked in AP ages ago!
Lovely.
Gonna use it as wallpaper, yourself permitting.

[Paul Haese]

Originally Posted by Andy01

Thanks for chiming in Paul, appreciate your taking the time to pass on some good feedback and tips. I used Noel Carboni's astro actions - increase star colours a couple of times - maybe I've overdone it there.

I took the stars in RGB at the Dark sky site too, and it seems they are a bit blown out compared to what I usually get from my light polluted suburban home in Melbourne. Looks like I overcompensated with the actions. I used the same 2 min subs so maybe next time I'll cut the exp time back when I'm at LMDSS - there's so many more stars there!

The flattener connection is screw threaded to the camera, but not screw threaded to the 'scope so it's not ideal - it's two or three pressure screws there so maybe that's something I can look into.

What do other people do in this case?

In regard to the star colour either use levels or curves to look at cyan. I don't think you have over done it; its more likely that a bias has come out because you have increased the saturation on the stars. Some tinkering should get it just right. Look at the histogram in colour to see the cyan and drop it until you disappears into the middle of the histogram. That ought to resolve the problem.

As to adapters: are you sliding into the focusor with whatever is in front of the flattener? Is so, you need to check two things. First, check the fit into the focusor. It should be tight but not overly so. You can buy aluminium shims that stick onto the flange. Make sure those are evenly spread around the flange. Three strips should be enough and running lengthwise. Next check your focusor for slop. This looks like a consistent issue so it is less likely to be the focusor, especially if you are crossing the meridian. So slop would show up in another corner in that case. Lastly, check the entire imaging train for any misalignment. It does not take much to throw out stars like this. A thousandth of an inch is enough to cause tilt. Use feeler gauges to test to see if everything is square. You will find the source of the problem by really investigating.

[Andy01 (Andy)]

Originally Posted by Leonardo70

Very nice Andy

All the best,
Leo

Thanks Leo

Originally Posted by RickS

An interesting rendition, Andy.

cheers Rick

Originally Posted by Waxing_Gibbous

Images like this are why I chucked in AP ages ago!
Lovely.
Gonna use it as wallpaper, yourself permitting.

Go for it mate - thanks for the kind compliment

Originally Posted by Paul Haese

In regard to the star colour either use levels or curves to look at cyan. I don't think you have over done it; its more likely that a bias has come out because you have increased the saturation on the stars. Some tinkering should get it just right. Look at the histogram in colour to see the cyan and drop it until you disappears into the middle of the histogram. That ought to resolve the problem.

Thanks for your input Paul - latest version here in High res
http://www.astrobin.com/157196/B/

I've worked on the star shapes and colours in Startools, it looks cleaner now cheers