This is a single 110sec exposure at f3.2, converted from RAW using Daylight White Balance then contrast-stretched on a grey-scale basis. Eleven Messiers in 110 seconds; a lazy boy's Messier Marathon ;-) As expected, the Lagoon comes out blue, rather than the usual red of H-alpha. I believe that the blue is from H-beta and OIII, to which the Canon 1Ds (and human vision) has much higher sensitivity than to the very deep red H-alpha. Anyway, I colour picked the blue and shifted it towards red. Presto! Most of the other nebulae follow suite. The labelling comes from The Sky software. Monsieur Messier sure picked a lot of nebulae and clusters, but I do believe there are quite a few more clusters in this picture that he missed... For more stuff peruse my primary website:
http://www.samirkharusi.net/