Thanks again for your comments. I think my Ha data was just too thin
to make much difference, but it did give me more experience in using
PixelMath to combine the Ha with Red according to guidance from Vicent
and Harry, as least as I understand it. I can see the result when I
compare the grayscale HaR and R, but the HaRGB doesn't seem to be that
much different.
The good news from this exercise is that I think I am slowly learning
how to use PI more or less intelligently in my processing, thanks to
all you guys on this great forum.
Dave