Blending Ha with RGB / Using Ha in L

[AstroTanja]

Recently I did LRGB and HA of the Gabriela Mistral Nebula, and I posted my 1st LRGB edit here on this forum. Since then I have edited the HA data acquired:
View here: http://www.astrobin.com/93467/
Original LRGB edit: http://www.astrobin.com/92853/

I am attempting numerous ways to do a HA and RGB combination. I've tried the NBRGBcombination script, which produced nice results, but the overwhelming red makes it a little difficult to saturate/edit the other colours without it looking too saturated in general.
I've played with various %'s of mixing the HA in with red, but would appreciate if someone has more pointers or tutorials I could work through. 

But what I would really like is to use the HA as Lum. It improves the detail tremendously (as pictured in this screen shot) but leaves the entire image looking too “salmon” coloured. Is it common to use HA in Lum?

Here is HA blended into the Red channel, as well as 80% blended into Lum:
http://www.astrotanja.com/wp-content/uploads/2014/05/NBRGB_plus_80HA20Lum.jpg
I've not edited it much further than the new LRGBcombination as my blue stars do not look right

I've tried various things, like removing stars from the HA to blend with the Lum, or use the HA straightforward instead of Lum – but nothing seems quite right. It also seems to cause problems with my mid sized blue stars, that have more of a blue glow around them when using HA in Lum. (I've tried a MT on the Blue channel before combining but it made no real difference)

Or I could possibly have been staring at the screen for too long. I don't know what looks right anymore. I know there is possibly no absolute right or wrong way, but would appreciate if someone had any insight or advice on what I should try. 

Thanks!

[Juan Conejero]

use the HA as Lum

That's a bad idea. The lightness component--because we are speaking of nonlinear stretched images, so there's no luminance--has a perceptual meaning. There's no relation at all between RGB data and Ha data in terms of perceived lightness and color. If you simply replace the implicit lightness of your RGB image with a (stretched) Ha image, the result will be "something" with a horrible pink color and damaged stars.

Mixing Ha in the red channel is also a bad idea, since by doing so you are damaging the stars and transferring noise from the broadband data to the narrowband data.

Take a look at this tutorial by Vicent Peris:

http://pixinsight.com/tutorials/narrowband/

In this tutorial, Vicent introduces a powerful concept for broadband/narrowband combination: the continuum map. There are other techniques using continuum maps with linear and nonlinear images, but this tutorial is a very good starting point IMO. I hope this helps you.

[AstroTanja]

use the HA as Lum

That's a bad idea.

Right - noted
I'll go back to the drawing board and post the result back here.

Thanks.

[mads0100]

Juan,

   When you post new tutorials, could you include some type of date and the PI version used? Just for archival purposes?

[Israel Gil]

Looking forward to have the implementation of this algorithm....   

Greetings.