I have been asked by a number of friends to post my introduction to Star Photography, so here it is.
As an example, here is a recent photo I snapped out of my back-yard:
Clicking through to the large versions will show the stars much better :-)
Here is my getting started guide:
1. Wait for a REALLY cold and clear night. Preferably with no wind otherwise you get blurry foreground features.
2. Get your camera on tripod. There is no way you can hand-hold this shot.
3. Focus your camera. You need to be on manual as auto will have nothing to focus on. Infinity is normally all the way to the end and back in just a little bit. If you have a bit of light in the far distance then focus on this.... the moon works or a star if you can find it. On my Canon 60D I can do a digital zoom (pressing the + button) twice to get right in and focus as accurate as possible. Now, leave the focus ring well alone, unless your hand slips and you need to refocus!
4. Take a test picture at the highest ISO you can and about 3" (3" = 3 seconds) or 5" exposure. This makes it nice and quick to get an idea of the composition. Keep testing until you like your setup. You can also check your focus.
5. When you are ready to take your real shot, drop your ISO down to the lowest you can get away with (you might struggle to get a clear picture at ISO100… so may need to compromise at ISO400) and drop your aperture to something reasonable like f8. Take a shot at between 15" and 30".. be sure not to move the camera at all. I use a shutter release cable. I should probably use mirror lock up as well.
6. Check and reshoot.
I am still playing with the whole ISO / aperture combinations to get the best shots. On focal lengths of 35mm - 50mm (maybe higher) I start to get star trails at 30" so want to adjust my settings so I can take the same shot down at 15". If you zoom into my image on Flickr then you'll see the star trails.
I think if you shoot longer, say 200mm then you can open the shutter for longer without star trail, but haven't fully worked that out yet.
Hope this helps. Anyone else who takes these types of photos, please feel free to jump in and offer your techniques / settings. I'll update this post as I get comments