NGC 6188 - Emission neb in Ara

[RobF]

Having read and seen much of this one on IIS, I've been keen to turn my scope on it and "have a look". On my 2nd night at the SPSP, for the last hour before astronomical twilight, I collected this data (while I froze my butt off :lol:).

Pretty happy with the noise levels considering only 2 frames of each colour to stack. One thing I learned at Wiruna is the wisdom of collecting at least 3 (preferably 5) frames of every filter. Live and learn.

LRGB 25:10:10:10 (5min subs no binning)
QHY9/MPCC on 8 inch Newt
FOV approx 1x 0.75 degrees (approx 1 arcsec/pixel)

2 versions attached. Brighter one was my first initial "hack and slash" effort, which I'm now thinking may be a bit smoother on the eye? Edit: Both versions have had some of PixInsights "Dark Structure Enhancement" run over them to bring out a bit more of the ummm.... dark structure.
Comments/critique welcome please.

[peter_4059]

Rob,

There is plenty going on in that FOV but I hear you when it comes to time spent on an object. I have come round to thinking max three in a night is a good target. The QHY9 seems to be going well. Are you happy with it?

[Hagar]

Very nice Rob. Collected quite a bit of nice clean and sharp detail in this image. This is not an easy target to capture good detail in and I am surprised how much you have been able to capture with just 10 minutes of each colour. Just imagine what you could have with say 30 min of each.
Well done.

[Octane]

Rob,

I agree with Doug that this is great for such little data.

This one has been bothering me ever since I started imaging.

I hope that the STL will offer me some comfort.

H

[RobF]

Thanks Peter. Very happy with the camera, and glad I made the investment. I think there's plenty within range to explore in high detail now and enjoying the new horizons (LRGB etc). Having fun anyway :)



Many thanks Doug. I'm probably bit too conservative some might think, but like to move ahead in small steps with new gear/techniques until I know I've figured something out. I set out to do a couple of objects for 4hrs and a number between 1-3 hrs at Wiruna just to see how I'd go. First chance I've had to collect decent colour data since I got the camera in January thanks to Qld weather, and pleasantly surprised have managed to get some half decent images from the camp to show for efforts.

[RobF]

In truth Humayun, the only reason this one made it on my imaging list for Wiruna were your comments earlier in the year about this being "a personal favourite", and the fantastic shots taken with the modded 40D + 127 apo (http://members.optusnet.com.au/mrozycka/Snake_Valley/Snake_Valley_20100313_NGC_6188.html ) (not to put down in any way the great shots of this one from many other IIS members - just mentioning what grabbed my attention at the time :))

[gregbradley]

You kicked a goal with that one. I like the 2nd version. The first version is a bit too dark for me and there is a green edge on the right side caused from stacking that needs to be cropped off.

The 2nd one is right on the money in my opinion. Good job.

Greg.

[RobF]

Thanks Greg. :D

Yes - realised after posting I hadn't done my final cropping to cut off overlapping filter frames. Apologies for tardiness.

I've been leaving this until the end lately in case I want to layer various versions during/after processing. Its surprising how often a quick "do it by feel" process turns out better than a clinical "follow the rules attention to detail" effort. Nice to be able to mix and match later without having to re-register images. Probably reflects the fact I've yet to get a decent LRGB workflow together more than anything though....

I think I'm going to have to explore separate star processing methods too - the Newt burns out bright stars so quickly alas - my only gripe with the 2nd one is it shows this a bit more.

[multiweb]

Beautiful shot. Well done. :thumbsup:

[Lester]

Very nice image, thanks for the view.

[bmitchell82]

Nice shot there rob.

I am with you on the Newt buring stars out, imagine the 10" 4.7.... it hurtles the photons in with a speedy sense to it!

I think the only way that you will be able to get the star colours to start playing ball with you is with 1 of 2 methods.

A. get a camera with deeper well sizes. allows longer exposures till max ADU has been achived.

B. use HDR and multiple length shots. eg, 10 5 3 1 min shots and combine them together with a HDR algorithim. but with LRGB... that could become a very very very long process :)

hope that gives you some ideas.!

[batema]

Hi Rob,

Yes I like the second one as well. I think it looks fantastic. Glad to hear you are loving the camera.

Mark

[RobF]

Thanks for looking Marc :)



Glad you enjoyed Lester!



No way I'm parting with my new baby any time soon Brenden, so will have to try option 2 some time. I know its a lot worse on fainter objects when I've had to stretch a lot more, so wonder about masking stars somehow (PixInsight should be able to do something with its Starmasks - just haven't got that far yet - studying here also dammit). I knew the 8300 was relatively shallow well depth wise beforehand, but couldn't pass up the temptation of getting one ;)



Thanks Adam!
Astrofest isn't that far away now....... :D

[h0ughy]

nice work Rob, obviously more time was needed but it is a very nice teaser to redo later with more data.

So how you finding Pixinsight?

[RobF]

Thanks David.
Yep, more than happy with the investment in PI, particularly while the Euro exchange rate was behaving. I'm gradually using it for more and more steps as I figure out how to do the things I want to do it in. This was also the first time I've manipulated L and RGBs separately all the way in PI, then used LRGB combine to bring them together in PI rather than PS.

My favs have to be:
- stacking (PITA to do it so labouriously, but does seem to give great results versus Maxim/DSS - could be just setting differences but I think it is actually "smarter" judging by rounder stars, and I'm sure they'll automate it more later)
- DBE
- Histogram stretch is really nice I'm realising
- ACDNR
- Saturation curves (this is my first image I've manually balanced RGB colours and Sat - still figured out colour cal)
- deconv (awesome!)
- Dark Structure Enhance was dead easy and nice to use on this one.

Have you played with the Animate.js script that Nikolay has put together? Its fantastic for flipping through cal'd and registered images if you're zoomed right in - every little flicker and tracking error is right there in hi res on painful display :lol: (Juan actually posted a movie of it in operation with music the other day....!)

Yep - I'm a happy camper :)