The Crescent Nebula (NGC 6888) with two channels, hydrogen-alpha and oxygen-three. 4 x 1200 second exposures for the Ha (mostly red channel), and 10 x 600 second exp. for the OIII (mostly blue channel). I didn't get nearly enough of the blue halo around the Crescent as I would have liked. I'll probably need to go to 20-minute exposures in OIII next time--or more 10 minute ones.