Combining Ha and OIII

[Nigel Ball]

Hello all

I've been happily processing my Ha and OIII subs in PI and I've even saved my first Process Icon  The Morphological Transformation tool wokred overtime on this wide field shot .....

Once I've got the images ot a decent state I'll want to combine them into RGB and generate a synthetic Green channel or create one using the Ha and OIII

I've had a good look through the forum but cant seem to find anyhting on this

Any thoughts / directions ?

Thanks

Nigel

[Silvercup]

Hi Nigel:

I used to do this pixelmath expresion:

R: H-Alpha
G: sqrt(H-Alpha*OIII)
B: OIII

Or you can play with percent in the green channel, for example:

R: H-Aplha
G: H-Alpha*0.15+OIII*0.85
B: OIII

Best. Silvercup

[Nigel Ball]

Thanks Silvercup

My first attempt produced a rather dirty yellow for the Ha using 0.8 Ha + 0.2 OIII 

I'll need to tweak the ratios to get a decent colour

Would I use PixelMath again to add the Ha on top of a RGB image for Luminance?

So many questions .....

Nigel