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alocky
03-12-2017, 07:46 PM
With all the moon about and the usual light pollution to the south I figured I'd have a go at a narrowband image of NGC2070. The Astrodons do a very nice job, and here's about 10 hours worth of SHO mapped to RGB. Owing to the strength of the Ha and OIII in this object, most processing efforst ended up blue-green, but winding the SII right up in the pixinsight AIP-SHO tool, and then playing about with Ricks selective colormask script I ended up with this result. I kind of like it, mainly because I've spend hours staring at a green version while cooking this one up.
Still -hardly respecting the light, is it? Anyway, I had a bit of a dig around and didn't see any renditions of this that weren't green, so maybe I should have left it as it was.
hi res on astrobin:
https://www.astrobin.com/324142/B/
cheers,
Andrew

Placidus
03-12-2017, 09:39 PM
Showing the distribution of the SII, rather than the abundance relative to Ha and OIII, is perfectly respectable and to be saluted. You've succeeded admirably. A lovely image, very sharp and deep.

I prefer the original, but Trish prefers the final version.

Very well done.

Best,
Mike

jenchris
03-12-2017, 11:30 PM
I'm a bit tired of green spiders.
I like yours.

alocky
03-12-2017, 11:33 PM
Thanks both Mike and Trish, as usual, your responses are thoughtful, considered and insightful!
It's definitely the spatial variation that makes this intriguing, what process created structure on such a large scale in the SII distribution is difficult to imagine.
cheers,
Andrew.

alocky
03-12-2017, 11:34 PM
thanks Jen :-) I know exactly how you feel!

astroron
04-12-2017, 12:51 AM
Very nice image Andrew:)
Do you know you can just spot Supernova 1987A as a pinkish star
below and to the right of NGC2044.
The small dark nebula with 3 stars in it below NGC2044, go straight down from it till you come too a small group of stars the pink one is SN1987A
Cheers :thumbsup:

RickS
04-12-2017, 08:32 AM
I like both, Andrew :) The Tarantula is always an impressive object and even better with a bit of focal length.

Something worth trying, if you haven't already, is to use LinearFit to match the Oiii and Sii to the Ha before combining. I often use that as the starting point for the colour.

Cheers,
Rick.

strongmanmike
04-12-2017, 09:00 AM
Yeah not baaad Andrew...but perhaps it just needs some more green....:question:

:face:

He he...nice work :thumbsup:

Mike

Andy01
04-12-2017, 08:52 PM
Hey I kinda like it too - except it looks more bicolour than HST - maybe gone a tad too far with the S2?
Kudos for breaking the "rules" and ther's some great detail showing. :thumbsup:

alpal
04-12-2017, 10:56 PM
Hi Andrew,
That's a top picture.
It's very difficult to process this target.
I would have used NASA FITS Liberator to do the stretching
but then again I don't have PI.
There are parts right at the center which should be brighter than they are.
The brightness is too uniform across the white & bright areas of the nebula.
I think you've lost some of the brightness information there.
As for the colours you can do anything with this nebula.
It definitely has unusual green colours in an RGB image
but yours is narrowband.
Thanks for sharing.

cheers
Allan

alocky
04-12-2017, 11:27 PM
Hi Ron - thanks for pointing it out! I did, I also snagged it in my 10" last year as well, but since this is a narrowband SHO image, it's the bright green star in the middle of the cropped image!

alocky
04-12-2017, 11:36 PM
Thanks Allan, I guess it's hard to know where to stop! The OIII signal is so strong in this object that OSC and modified DSLRs still have a hard time rendering it in red.


I'm hearing it needs more green...


Yep, definitely needs more green. OK I've put a little bit back in...


Thanks Rick, I had a go at the linear rescale prior to stretching, combining, but it didn't seem to make that much difference as I'd been eyeballing the curves and trying to equalise them anyway. Still, I didn't know that tool even existed and it is easy to use! Since I'd gone back to the AIP script I figured I'd give it another go...

Atmos
05-12-2017, 07:06 AM
It’s quite an interesting rendition Andrew, it is not often that the SII signal is strongly enhanced.

Prickly
06-12-2017, 04:21 PM
Looks great Andrew. I like your most recent version. That’s one way to sort out the street lights with the astrodons! Nice detail and good sharp image. cheers David