The Trifid is a combination of emission nebula (the red) reflection nebula (the blue) and dark nebula (the dark rivers blocking the light fron the red and blue) this combination gives the image a 3D effect. Losmandy G11 guided, CanonXTI self modified, ISO800, 10 exp., 240 sec. 5darks, 5 flats,5 bias. Images Plus3.75, CS2.