This year's M51 is in colour, this time with my new Astronomik RGB II filter
set. It lets more light pass than my old filters. I combined the red channel
with a Halpha picture to bring out the HII regions more clearly.
Conditions were good for city standards.
Taken from the middle of Berlin with an 8" LX200, MX716 camera, video
autoguider, luminance 15x10 minutes at f/6.3 with Astronomik CLS filter,
colours at f/4 red 2x10 minutes + 10 minutes Halpha, green 10 minutes, blue