Astrophotography (literally photographing stars, but it usually includes all kinds of celestial bodies, such as nebulae and galaxies) is a great hobby, but it can be quite challenging for the beginner. However, with a bit (lot) of patience and the right equipment most difficulties can be overcome. Here's a brief introduction;

1. Camera

The first thing you'll need is a single lens reflex (SLR) camera, with either a long exposure setting or a manual shutter release. Compact cameras are unsuitable, as they usually lack the possibility to do long exposure or manual shutter release, and getting the right focus might be problematic as well.

2. Mount

The next step is to get a stable mount for the camera. Since we're talking about very low light levels, you'll need a camera that can cope with long exposure times. With long exposure times, however, the image is very susceptible to vibration and movement, and it's easy to end up with bright streaks instead of stars. And, to complicate things further, the celestial sphere rotates (15 degrees per hour), so when dealing with exposure times of more than, say, 30 seconds, you actually need to rotate the camera along with the sky. See below.

When taking pictures you can rest the camera against anything solid, such as the car, or place it on the ground in a stable position. It's recommended to get a tripod, though, as you'll have much better control of the aim and field of view.

3. Barn door mount

If you want to take shots of really dim objects, such as nebulae, clusters, comets and galaxies, or just generally spice up your pictures, you might need to use exposure times of anything from several minutes, perhaps up to a few hours. But as mentioned, the sky rotates, so we'll need something that rotates along with it. The "barn door mount" to the rescue!

Making your own barn door mount is pretty easy. You'll need two pieces of wood, a good hinge, some screws and a ball-and-socket camera mount. The two pieces of wood are joined by the hinge, the camera is mounted on the top side, and the tripod is mounted underneat. (If you search the net for "barn door mount" you can easily find more detailed building plans.) The principle is the same as with a telescope on an equatorial mount; if you point the axis of the hinge towards the pole star, the "door" will "swing open" in the same direction as the sky rotates. You will need to use a screw to control the angle, though, as you need to be pretty accurate.

4. Taking it up a notch

More experienced astrophotographers might try different approaches, such as "piggybacking", i.e. mounting your camera onto the tube of a telescope, photographing through the telescope (adapters can be found for most cameras), and digital photography using either a regular digital camera or a CCD camera specialized for low light levels. Other tricks of the trade include filters, to remove unwanted light pollution or to emphasise certain parts of the spectrum.

5. Conclusion

All in all, it doesn't have to be very difficult, nor expensive, but it will take a bit of trial and error. But the reward for patience is stunning pictures, and impressed friends.