1.15. ISO

ISO, or sensitivity, can be raised or lowered easily on most digital cameras. The current generation of cameras handles high ISO settings much better than older cameras, and this technology is getting better all the time.

So one approach to night photography is to boost your ISO like crazy. If you could shoot at ISO 50,000, then the darkest corner of the world would be no obstacle . . .and to heck with tripods and extended exposure times.