NGC 6888 narrowband colors

NGC 6888 narrowband colors, a photo by Urlaubsknipser on Flickr.

Via Flickr:
NGC 6888 shown in H-Alpha, OIII and SII, all taken with Astronomik 12nm Clip-In filters in a 500Da. Exposures were:

8:10h H-Alpha 12nm
5:20h SII 12nm
4:45h OIII 12nm

Clearly H-Alpha is much stronger than the weaker OIII and even weaker SII channel.

Three color combination schemes are presented: A synthetic RGB, the well-known Hubble Palette and a modified Hubble Palette which reduces the dominance of H-Alpha and better shows OIII contribution.