Gum 12b - RGB_Ha_SII

[Ryderscope (Rodney)]

This image is centred around the nebula Gum12b located in the southern constellations of Antlia and Vela and captured with RGB Ha and SII filters. Only a few OIII subs were captured initially sufficient to conclude that there wasn’t much in the way of OIII to be had though I'm leaving the option open to visit this again.

How to combine Ha and SII into a meaningful colour image led to some head scratching for a while given that both of these emit radiation in the red band. The processing objective was to try and produce a natural looking image that highlighted the different structures present in the Ha data and the SII data. I managed to do this be mixing the colour channels using the Pixelmath process in Pixinsight to mix Ha and SII across the Red and Green channels and creating an artificial blue channel with the Ha data. The net result is that Ha predominance shows as orange/red in the image and SII predominance shows up as a yellow to gold colour. RGB stars were added in to create the final image.

Link to image on Astrobin here.
Full acquisition details on Astrobin post.

Clear skies,
Rodney

[Crater101 (Warren)]

Having looked at the Astrobin image and information, I'm not surprised that you got such a great result with 37 hours of data (although how you got clear skies for that length of time... )
A fine image indeed!

[Ryderscope (Rodney)]

Originally Posted by Crater101

Having looked at the Astrobin image and information, I'm not surprised that you got such a great result with 37 hours of data (although how you got clear skies for that length of time... )
A fine image indeed!

Thanks Warren. You are right about the weather, there doesn't seem to be many clear nights to be had lately. These data were collected over February/March and I was obviously fortunate enough to get enough clear nights. Being a southerly object helps in being able to get at it for most of the night plus having the gear set up at home so no need to travel.

CS,
Rodney

[strongmanmike (Michael)]

Wow very cool, like a big flame and interesting processing recipe there too, clever, sounds a little like alchemy ...and you have clearly managed to make some gold there! well done.

Reminds me a lot of SH2-312 in Pyxis

Mike

[Ryderscope (Rodney)]

Originally Posted by strongmanmike

Wow very cool, like a big flame and interesting processing recipe there too, clever, sounds a little like alchemy ...and you have clearly managed to make some gold there! well done.

Reminds me a lot of SH2-312 in Pyxis

Mike

Thanks Mike. I like the concept of alchemy. Sounds very apt with what we do in mixing colour palettes for narrowband processing. I'm drawn to your image of SH 2-312. It makes for a lovely composition. I shall be adding this to my target list.

[strongmanmike (Michael)]

Originally Posted by Ryderscope

I'm drawn to your image of SH 2-312. It makes for a lovely composition. I shall be adding this to my target list.

With your wider field, you should be able to compose a super shot of it, perhaps about the size of the square at the top here?

Mike

[Ryderscope (Rodney)]

Originally Posted by strongmanmike

With your wider field, you should be able to compose a super shot of it, perhaps about the size of the square at the top here?

Mike

That's looking very interesting. Because of the position angle of my camera I would need to do a two panel mosaic. Definitely worth a shot.

[Startrek (Martin)]

Rodney,
Always admire your wide field work , so clean and detailed
Of course dark skies , a stable atmosphere and a boat load of data helps a bit together with a skilled astrophotographer.
Colour palette is excellent, sort of tongues of flame red.
Unfortunately a lot of objects are abundant in Ha and extremely weak in Oiii , however with some clever channel compositing and layering you can create some wonderful colour palettes with only Ha and Sii , and this image is no different. The golden hues are stereotypical HST palette and always provide character.
Well done !!
Martin

[Ryderscope (Rodney)]

Originally Posted by Startrek

Rodney,
Always admire your wide field work , so clean and detailed
Of course dark skies , a stable atmosphere and a boat load of data helps a bit together with a skilled astrophotographer.
Colour palette is excellent, sort of tongues of flame red.
Unfortunately a lot of objects are abundant in Ha and extremely weak in Oiii , however with some clever channel compositing and layering you can create some wonderful colour palettes with only Ha and Sii , and this image is no different. The golden hues are stereotypical HST palette and always provide character.
Well done !!
Martin

Thanks Martin. It can be quite a challenge at times to develop a palette that reflects the underlying physics whilst presenting an aesthetically engaging result. I did note from this and a couple of recent projects that there can be a strong correlation between the Ha and SII signal with minimal Ha present. We then have to decide whether to just stick with the traditional RGB Ha or to maybe try something different.