I did a Halpha image of NGC 7635 last year and added some RGB this year. I
had to do a 50/50 mix of the red channel and Halpha, otherwise the image
would look washed out with a pink hydrogen nebula.
Taken from the middle of Berlin,
luminance with a C8 at f/7, G11 mount, SXV-H9 camera, 36x10 minutes through
an Astronomik 13nm Halpha filter,
RGB 6x5 minutes each with an 8" LX200 at f/4.4, SXV-H9 camera.
The image can also be found at
http://ccd-astronomy.de/temp/7635colourgut.jpg
Halpha:
http://www.slilge.de/Sharpless/7635-36x10gut.jpg
RGB:
http://ccd-astronomy.de/temp/7635RGBgut.jpg
Stefan