ASTRO: Abell 39 (PN in Hercules)
I wanted to do one narrowband-target in the clear nights in early May and
Abell 39 came to my mind. So far I only had a b/w version.
I binned all frames 2x2 which makes me background limited with the OIII
filter even at f/8. I also did some RGB frames for star colours, but didn't
use them as stars didn't look much better in RGB than in Ha:OIII:OIII.
Taken from Berlin with a 10" Meade ACF on an AZ-EQ6 mount, Trius SX694
camera, 52x10min OIII, 14x10min Ha.