Pickering's Triangle - Additional 3 hours 20 mins

[gnomus]

Using Channel Combination (just as you do for RGB).  Leave it in RGB combination.  Put Ha in for Red, OIII in for Green and Blue - click the circle.  I do this before stretching (whilst still linear), which is what I do for 'normal' RGB combinations and so I assume is correct.

[gnomus]

2 hours ago, ollypenrice said:

I don't do 'NB only' images but do combine Ha and OIII with RGB ad LRGB. A system I use might be of interest, though. It's all to do with how much of which filter to map to which channel. In Ps you can build up a system of layers, a stack of different mappings using layers, and then vary the opacity of each to see, in real time, the effects of the blends. So you might, for instance, in the 'RGB' channels stack something like:

Ha, (blend mode luminance)

Ha OIII OIII (blend mode normal)

Ha OIII Ha (justifiable on the grounds that H beta, which is blue, traces the same gasses as Ha.) Blend mode normal.

The opacity slider would then give you a real time blend.

If you NB types are already dong this then I'll slink away with apologies...

Olly

Olly.  If I got some RGB of Pickering could I combine this using your method with my NB data, and would it look similar to my HOO only image, but with 'proper' star colour?

[ollypenrice]

9 hours ago, gnomus said:

Olly.  If I got some RGB of Pickering could I combine this using your method with my NB data, and would it look similar to my HOO only image, but with 'proper' star colour?

You could, and it would be similar. It should work well. In fact there is strong blue signal which may be reflection rather than simply OIII and H beta (which a blue filter will pass) so you might have RGB, particularly B, adding to the nebulosity as well as the stars. The nice trick we worked out with the Seagull was making the three layer stack

R G-OIII B

RG B-OIII 

Ha-R GB

...so as to be able to weight the OIII balance between green and blue.

Ha as luminance needs to be handled with great care and applied sparingly over RGB. It risks diluting the red colour, subduing the green and blue and giving blue star halo artefacts.

Olly

[gnomus]

Thanks again Olly.  I may give that a go at some point - but I'm knee-deep in the Pacman at the moment.

[Singlin]

In Pixinsight Channel Combination it says no compatible files.

I have my Ha and OIII files open in pixinsight they are .xisf extension

[gnomus]

That is odd.  Have you star aligned and dynamic cropped them?  (You know you can apply the same dynamic crop to aligned images, don't you?).  If you want to Dropbox them I can have a go later if you like.

[gnomus]

The only other thing I can think of is to ensure that RGB is selected.  Mine looks like this:

[Singlin]

I had cfa images checked in the batch processing menu as the last run I did with a DSLR camera.

I unchecked it and did my batch processing again and all is well.

Thanks.

[gnomus]

Great stuff.

[gnomus]

Thanks all for the encouragement.  I got notification today that 'Astronomy Now' are going to publish the picture.

[nucdoc]

I have returned to this thread countless times to admire this image, just stunning !

[gnomus]

Thank you.

[Knight of Clear Skies]

Wonderful detail, really captures the shock fronts at that focal length and depth.

I look forward to the mosaic of the entire Veil Complex. /runs

[Twisted Lip]

Well I must say that image sinks into my eyes like a velvet smooth optical whisky, it is simply stunning!
Cheers
Will

[Tom OD]

Lovely and smooth image, with a super O3 signal. Great pic.

Tom

[gnomus]

Thanks all.