Reflection and Dark Nebulae in Corona Australis

[Octane]

Hi all,

Well, here it is. My first image from my partially-automated exposed backyard observatory. :D

This image comprises 20.73 hours of data captured over 23 nights in June, August and September. 10 hours of luminance, and, the rest in red, green and blue data.

It's been a long time coming. I travel 1.5 hours each way to work and back and by the time I get home, I'm so tired I can't even begin to think about processing images. I still have my 8-panel Rho Ophiuchus mosaic data staring at me waiting to be processed. It's going to take me a year to get through it all.

Very happy to see dust surrounding the main dark nebulae. I haven't seen it before (or, if I have, I didn't pay much attention to it). I am hoping that's a result of the ten hours of luminance that has given it some prominence.

I hope you like it.

Image is here (http://scratch.hqphotography.com.au/ca_c.html).

If you click on the image, it'll load a 50% resolution file.

Comments, critique, etc., most welcome.

Thank you for looking!

H

[Shiraz]

wow!. what a beautiful image - very nicely done :thumbsup:.

[marc4darkskies]

Oh yes! That's a keeper alright! Well done H!! :thumbsup:

PS: C'mon now H, let's see the full res!!!

[strongmanmike]

Great vista that H, the main dust and reflection neb really look excellent

Lot of work in there mate, great effort :thumbsup:

One thing though, I note the bands of what appears to be broad swaths of faint featureless dust on either side of the main nebula, I haven't seen this before and after a scan of several wide field shots of this area couldn't find another image showing it :shrug: do you think it is real or could it be a processing artifact or maybe flat field issue..?

Mike

[gregbradley]

Beautiful image H. Very detailed and nicely processed. I'd say those features are real. Most examples are shortish exposures and flats wouldn't create a dust colour look, more an uneven look. The dust colour is spot on.

Greg.

[marco]

Lovely wide field of this classic H, the framing is quite particular too, this way it resemble to me an insect of some kind, a fresh perspective :thumbsup:

Clear skies
Marco

[nebulosity.]

Beautiful :thumbsup:

Jo

[Saturn%5]

That is sweet, Well done H:thumbsup:

[sjastro]

Beautiful image H.

Steven

[atalas]

Looks great...good work H!

[Paul Haese]

Nice image H. Good colour and lovely field of view.

Re the dust. Do you mean the dark band that travels along the nebula to the left which also encompasses the globular?

I think this is just an absence of dust and hence why it stands out. There is dust over the entire frame in your image and where there is an absence of that dust it stands out.

If on the other hand you are referring to the dust just immediately left and right of the dark dust then, this is a common feature and seen in lots of images, though only those that are deep. It's well seen in my recent image of the area. Though I suspect this is not the dust you are referring about.

In any event, a lovely image of this object.

[RickS]

That's a stunner, H! A fitting image for your return.

Cheers,
Rick.

[gvanhau]

Very nice and a lot of work.

The framing is very particular, as of you were planning a 2 pane mosaic (continuing at the bottom)?

Geert

[PRejto]

Bravo! Your dedication has really paid off and the processing I'm sure also took a lot of effort and thought. You seem to have nailed it!

Peter

[multiweb]

Nailed it. Very deep shot H. Great field. That's dedication. :thumbsup:

[Larryp]

Great image, H! Looks almost 3d:thumbsup:

[graham.hobart]

Very very cool H. Superb finish.
Graz

[Octane]

Ray,

Thank you!




Marcus,

Cheers! It's good to be imaging again. :)

When I get a moment, I'll put up the full resolution image.



Mike,

Cheers! I initially thought it was dodgy flats, too. But, I used DBE in PixInsight to extract the background in both the RGB and luminance images. It removed the gradient that was there and it's left me with this. Perhaps it is an artefact? I'm not sure. Might need to reprocess and see if it pops up again? Having said that, these same sets of flats have been used on other images that I've been working on and they seem to be void of this... who knows?



Greg,

Thank you! The colour was largely due to PixInsight's ColorCalibration routine. I selected an area near the globular cluster that I knew was dark and used that for my sky background. I used the entire image as the white reference. It spat the colours out and my jaw dropped. :)



Marco,

Thank you! Yes, the framing was a bit serendipitous. I had taken sky flat frames for my colour filters at that particular orientation for my Rho Ophiuchus mosaic and I didn't want to rotate the camera which would have meant taking more sky flats. And, because I was still capturing data for my mosaic, I didn't want to rotate the camera; I'd have to take yet more sky flats.



Cheers, gents.

H

[Octane]

Jo,

Thanks, mate!



Graeme,

Many thanks. :)



Steven,

Glad you like it. :D



Louie,

Thank you, so much. I still remember, the first time I imaged this region was with a 200mm lens, and, it was at the Paintball Place. You were there, all those years ago. :)



Paul,

Many thanks!

I was referring to the stuff on the outside of the dark band. I am happy to be corrected if it is processing artefacts (dodgy flats?), but, either way, I'm quite happy with the way this has come out.

The first thing I did when I finished processing was to look your image up to see how the colours matched up. I think it's pretty close. :)



Thanks, gents.

H

[Octane]

Rick,

Thank you! It feels awesome being back in the saddle again. :)

I might have to start taking my MacBook Pro on the train to start working on Rho Ophiuchus. There's so much data just sitting there looking at me!



Geert,

Haha! You caught me out! I indeed did want to mosaic this area, but, between this and another project, I ran out of time. So, I decided I would just devote the 20-odd hours to this one panel. As it turns out, it's come out half-decent. :)

Thank you. :)



Peter,

Really appreciate the kind words -- thank you. :)



Marc,

Cheers! When is your new scope going to be commissioned?



Larry,

Thanks!



Cheers, gents!

H

[Octane]

Graham,

Many thanks. :)



Thanks, again, all!

H

[tilbrook@rbe.ne]

Beautiful work H!:thumbsup::thumbsup::thumbsup:

Bench mark I think, especially colour and detail.

Cheers,

Justin.

[Regulus]

A beatiful image Humayun. Great colour and there's some good depth, esp in the thick dust cloud.
Well done.
Trevor

[strongmanmike]

Hmmm? dynamic background extraction huh? I dunno...never have trusted that...bit like deconvolution :question: I recon it might put in as much as it removes :lol: There are many wide field examples of this area out there but I can't find one that shows these features :shrug: can anyone else?

Here (http://oldweb.aao.gov.au/images/624x832_caption/uks037_72c.jpg) is a deep AAO image with no sign of them..?

It's the two large faint brownish vertical swaths or bands on the left and right sides of H's image? I mean, yes, it does look kinda real but I have just never seen them before... and it's not as though you have done a super long exposure from a super dark sky or anything (although over 20hrs is nothing to sneeze at)...oh well, as you say, who knows, could be like my mysterious NGC 1232 jet :scared2: :lol:

Regardless though it is a great looking image and I hope I don't sound like I am picking on the image, I'm not :thumbsup:...just intrigued :)

Mike

[Ross G]

A beautiful photo H.

Sharp, detailed and great colour.

I think the dust on either side is real.
I took a similar photo 2 years ago, same fov and composition, and I could see the dust I think you are referring to.
Mine was processed with Photoshop CS2 so no PI involved.

Great work.

Ross.

[Rod771]

Great start with your new set up, very nice image H!:thumbsup:

I'm looking forward to the Rho Mosaic, love that part of the sky.

[Octane]

Many thanks, guys!

Rod, it's an old setup, I just haven't had much chance to use it, that's all. :)

The camera is going to be sent to the US next week for some surgery. So, I'm stuck with DSLRs in the meantime. Going back to my roots! :D

H

[Andre27]

Very well done , the detail is great , very good color.

[NOMH]

Great field! A very well balanced image.

JB

[Octane]

Thank you Andre and John. :)

H

[Octane]

Update:

I took into consideration what Mike Sidonio mentioned about the artificial halo surrounding the object. I went and looked through my preprocessed data files and noticed that the individual RGB files had "ABE" in their names! I had used PixInsight's ABE rather than carefully-placed DBE samples. The haloing was evident in my individual RGB ABE masters when I opened the files up and had a proper look at them.

So, I just spent a few minutes tonight re-doing the data and using DBE instead of ABE. The end result is a flat image that looks even greater than the original process.

This is straight out of PixInsight and needs to go to Photoshop for final processing.

I was creating drizzle data and I inadvertantly trashed all my green data, with no backups! So, I did the traditional upsample of RGB by 2, instead of being able to drizzle it; drizzle has given me amazing results with other data sets I've been working with. Oh, well; I'll just have to recapture this next year.

I might be on to something with this one.

Click here (http://scratch.hqphotography.com.au/ca960.html) for updated image.

I've also added the image underneath the image in the original link for direct comparison.

Cheers.

H

[Andy01]

Thats cool, looks like an orangutan's face!
Nice work H.

Andy

[Rex]

Spectacular image H. I am currently working on a mosaic of this object, and I must admit it is a very challenging object to process. You have done an amazing job of showing how beautiful an object it really is. I was doing some reading about it the other day (as I do with most objects I image), and its actually one of the closest star forming regions to us. That main dust cloud is full of very young protostars apparently. Must be visible in IR or something, otherwise how would they know? Anyway, awesome shot mate, with excellent processing.

[RobF]

Great work H - I was looking over your original image tonight worrying about the dust on the left side of the frame amongst other things. This image seems more balanced, and you've achieved a wonderful subtle processing of the dust.

The blues seems just a bit overexposed in this latest one?
Heck, enough of that - stunning image :thumbsup:

BTW, are you going to AF?

[marco]

Lovely field H, so packed of stars that it is always difficult to process the dust keeping them tiny :) I guess a vertical framing would have helped to image of bit more of the long dust tail of corona australis, but it is very nice as well in landscape as you did it :)
Clear skies
Marco

[Octane]

Many thanks, guys!

Marco, I'll make a mosaic next year. :)

Rob, yep, this was a rough process straight out of PixInsight; I will be mindful of all the channels as I process it thoroughly.

Sadly, I won't be attending Astrofest. Too much on with work. I don't have any leave (bring on long service leave in April!) and never even thought about asking for a domestic visa. :P One day...

H

[RobF]

Oh well. We'll suck down some photons for you.

Yep, those domestic visas can be the hardest of the lot to negotiate. I've been told brownie points have a very short half-life... :D

[strongmanmike]

Excellent repro Humayun, told ya ;)

I agree with Andy, first thing I saw too...Rafiki the Mandril :)

Mike

[Paul Haese]

Hi H,

I like this reprocess and it really shows the nebulosity well. Dust colour is very nice and star colour is ok but I think you have a little too much magenta in the star colours. If that was toned down a little you would have one hell of an image of this region.

BTW your full res image which is linked to the smaller resolution image on your website is of the old image I think. It is a completely different colour in the dust.

[rustigsmed]

wow - that is simply stunning H :eyepop:

[Nicola]

Very pleasant indeed, well done!

[SkyViking]

Looking fantastic H. That's a lot of dust, and really pleasing colours too. PI is a wonderful tool indeed :)
BTW as Paul said, the linked full res image appears to be the original version still.

[Leonardo70]

Very nice. Congrats.

All the best,
Leo

[jase]

Not an easy target H. Your persistence has paid off with a great image. Your skies better now you've moved back down south again?