Help with NB Workflow & HST Palette

[AstroTanja]

Hi everyone.
I recently migrated to narrowband imaging, and struggling to get the hang of my channel combinations. My 1st attempt of the Carina nebula was acceptable https://www.flickr.com/photos/astro-tanja/12910032393/, but my recent image of NGC 6188 doesn’t resemble anything I was expecting.

1.) What is the proper combination, pre or post stretching? I have seen tutorials both ways

The image attached here (or high resolution here: http://www.astrotanja.com/wp-content/uploads/2014/07/ngc6188_preview1_2.jpg) was stretched and then combined in PixelMath using the HST Palette. This is a quick edit as I’ve been playing with linear and non-linear combinations and various other edits - so excuse imperfections & noise.
I used the following processes to get to this result
   Calibrated&registered / DBE on individual channels / MT on SII
   Histogram stretch
   PixelMath to combine stretched channels R=SII, G=HA, B+OII
   ABE
   Curves / Saturation
   LocalHistogramEqualisation
   Histogram
   MMT & UnsharpMask
I know there’s a lot more to this in processing, but colour is my concern now. Do I treat combining the NB in the same fashion as LRGB? And do the same regulars, like CC and SCNR apply?

2.) But the important question: Very many posts I have found online, that were done in HST palette looks almost the reverse colour of mine. The blues and orange/gold tones were initially what I was after. Example this APOD: http://apod.nasa.gov/apod/ap100716.html
It doesn’t matter which combinations I try within the HST pallet, I can not get to this result.

Can anyone advise where I am going wrong with channel combination on this NB image?
Much appreciated.

[pfile]

i think vicent recently posted a link to a narrowband image he did at a workshop where he covers this.

https://pixinsight.com/workshops/cfa-2014/munich-03.html

there's no workflow there, but the key idea is color correction on the entire nebula.

doing a ColorCalibration on the whole image seems to bring an SHO image into the right color regime. then an SCNR to the green channel kind of finishes the job. also the curves tool (*a and *b) can be very helpful in tweaking colors.

i have not really published this image because i was just messing around and used completely uncalibrated frames as inputs, but it was done with the above technique.

http://www.astrobin.com/107496/

rob

[Alejandro Tombolini]

Hi,

and also this processing example can be usefull.

Saludos, Alejandro.

[AstroTanja]

doing a ColorCalibration on the whole image seems to bring an SHO image into the right color regime. then an SCNR to the green channel kind of finishes the job. also the curves tool (*a and *b) can be very helpful in tweaking colors.

Thanks. I'll check out the links.
I keep on not getting the best ColourCalibration, however my attempts seem to be improving. And I think this is possibly the cause of my headaches. Thanks for the advice, if I post a new edit I'll put the URL here too.

[AstroTanja]

and also this processing example can be usefull.

Perfect, thank you for sharing!