Night Vision Devices are now being used with telescopes to increase the image brightness and detail available to the user at the eyepiece. They seem to be a revolution when it comes to Ha nebula! - Thanks to @GavStar for opening my eyes to this emerging art of "Black Ops Astronomy" with his revealing phone images of bright nebula from central London.   I decided that I wanted to give this a try especially as I own a very fast focal ratio dobsonian. Two main factors were foref