So what is the GO with blending Ha with RGB. Given Ha is at the deep red end of the spectrum and you have also shot Red. Are you using it as Luminance, what if you shot L as well? Where does it fit in? I recently imaged NGC2029 in LRGB and added Ha to bring out the arches and detail only available using that filter. I assume that is the primary reason to capture detail not available in broadband filters, to enhance structure. However, what colour, if any, are you assigning to the Ha. I played around with my image an finally used a bit of magenta. Is it just 'artist' license, do what you like, etc?