M 17, The Swan Nebula (Sgr)
Technical data: 16"f/8-Hypergraph
STL6303 with Astronomic filter set IIc
HaRGB (Ha (12nm) = 4 x 900s; R and G = 3 x 300s; B = 3 x 600s)
Authors: Bernd Flach-Wilken and Volker Wendel
Comment: same data as above, here is the H-alpha channel displayed for itīs own.