One of the reasons I hauled my big tripod/ball head combo all the way to Tanzania is I wanted to try out some star photography. Living in Vancouver, I simply can't see that many stars due to light pollution. I knew being out in the bush in East Africa would give me opportunities for night photography that I just don't get at home.
This shot was taken at the first camp site I stayed at, in the Ndutu part of the Ngorongoro Conservation Area. We were situated among some beautiful acacia trees and I wanted to try and incorporate them into the shot.
To get lots of stars, you need a lens with a wide aperture (f/2.8 or wider is preferred) and a wide angle is nice to capture as much as possible. This photo was a 30 second exposure which was long enough to capture lots of stars but not so long as to start capturing star trails. ISO was at 6400.
I had a lot of fun messing around with this and am considering taking the next step. To get your ISO down for cleaner shots, you need a longer shutter speed. To do that and avoid star trails, you can buy equipment that will actually move your camera along with the rotation of the earth, such that the stars will stay put during your exposure. Now you can do a 4 or 5 minute exposure at a much lower ISO and still come out with more detail and a cleaner image. Definitely something I'm considering though it'll mean getting out of the city more and finding some dark skies!