I have used the HaRGB process with good success, documented in several areas on the net. By fiddling with percentages on the LRGBCombine, I finally get the colors I want with the clarity and nebulosity of the Ha channel. I use a copy of the Ha as luminance.
* Process Ha and RGB images through non-linear stretch (DBE, Background Neutral, Color Cal)
* I copy the Ha to use as a luminance later; do Deconvolution (if beneficial) and sharpen the Ha luminance, put aside
* Extract the channels from the RGB image, discard all but the R
* Use the following formula in PixelMath
((HA * Red_Bandwidth) - (R * HA_Bandwidth)) / (Red_Bandwidth - HA_Bandwidth)
HA - HA Image (original, not sharpened one)
Bandwidth of my red filter is 100
R - Extracted red image
Bandwidth of my Ha filter is 6
You can experiment and drop the bandwidth of the red.....I usually use 75. Make sure you Create New Image - the resulting New Image can look a bit funky, but that is OK.
Next combine the extracted R with this new image to produce a hybrid HaR image, use this formula in PixelMath:
R + ((New_Image - Med(New_Image)) * Boosting_Factor)
The only variable here is the boosting factor, I use between 4 and 6; the higher the number, the more the Ha contributes to the HaR hybrid.
Use this new hybrid and recombine with your original G and B images to produce the HaRGB.
I then use LRGBCombine to combine this new image with the sharpened Ha I am using as the Luminance. Experiment with the weights to get the color right.
To combine OIII data, use your OIII and G bandwidths, and the extracted G channel, in place of Ha and R. Hold off doing the RGBCombine until you have the HaR and OIIIG hybrids, and combine with the blue channel.
This process always works well for me, I don't get the pink salmon appearance in the red channel, or too much green as in a straight HaOIIIB image.
Joe
