Just to show what is possible and giving some hope to beginning astro photographers
This is M42 taken on a crappy night with moisture in the air, as can seen by the nice blue halo around the brightest star right of M42
The advantage for me is that i have a QHY9, but this is also possible with a dslr and some longer exposures.
Here we go: Red=7x30Sec Green=6x30Sec Blue=7x30Sec and Luminance=13x30Seconds
I have only done levels,curves and noise reduction in CS5
The black point is a wee bit cut but i dont care
To have a look at how it is done go here and try some of those techniques --->>>
http://www.newastro.com/zone/downloads/index.htm