Hi, I took this back in June 2007, finally got around to processing it last night. Taken with 18"Newt,QHY8 camera, 1xhr RGB, 2hrs x Ha, processed in PS. Still not sure of the best way to add Ha and RGB data with a one shot color camera. Sorry I haven't posted for a long long long time but my new years resolution is to try much harder .........
Nice work Ken. I think the best way to do OSC Ha is to split the RGB data, then add 10 to 20% Ha data to the R channel to create a new one. Once this is complete re-add it to the GB channels (as a new channel). Then continue to use the Ha as a luminance. You could do most of this in Photoshop. The only concern you may have is rebalancing the new [HaR]GB composite. A bit of trial and error would be required as I'm not familiar with your set up to advise the best method. OSC still need to be colour balanced too. If your stars go weird, simply re-layer the original RGB over the top. Look forward to seeing more.
Thanks for your kind comments. Most articles I have read on adding Ha data to RGB seem to be based on mono chips. I tried adding the Ha as a BW to the red channel in RGB but ended up with weird star colors. In this image I think I ended up leaving the Ha as a red image and adding it to the RGB using the screen function in layers pallette. I think I over processed the image trying to get the faint detail making it a bit grainy. I had and extra hour of Ha data but it was lost when my laptop hard drive died. Anyway, thanks for the comments, I might try reprocessing this image with some of your ideas.
Clear skies
You may need to blend more Ha into the red channel Ken. The Ha details appear a little muted. The latest revision seems to have brought a little more colour back into the stars.
You can also trying the luminance layering technique by adding the Ha image as a luminance layer to the RGB, but only at 50 or 60 percent. Then flatten the image (which creates a super RGB) and add the same Ha data as a luminance layer again, but this time at 100 percent to get as much detail as possible. May need to boost saturation as you go with either shadow/highlights or saturation. Note, shadow highlights performs a non-linear stretch on the data whereas saturation is linear (the equivalent of levels). Keep this in mind so you know what you are doing to the image. Excessive use of saturation will excessively lower the white point introducing star wash etc.
Keep at it. Don't be afraid of experimenting to see what works well. Every image is different.
Thanks for your kind comments. Most articles I have read on adding Ha data to RGB seem to be based on mono chips. I tried adding the Ha as a BW to the red channel in RGB but ended up with weird star colors. In this image I think I ended up leaving the Ha as a red image and adding it to the RGB using the screen function in layers pallette. I think I over processed the image trying to get the faint detail making it a bit grainy. I had and extra hour of Ha data but it was lost when my laptop hard drive died. 
Anyway, thanks for the comments, I might try reprocessing this image with some of your ideas. 
