Astrophotography is a type of specialized photography which entails taking photographs of celestial bodies such as the moon, stars, planets, galaxies, nebulas, and any other celestial objects.
For the beginner, it's not that difficult to get started. If all you want to do is to take pictures of the night sky, just an inexpensive digital camera will do. If you want to take pictures of celestial objects such as planets and see them close up, you will need a telescope as well.
The least expensive start-up set would be an inexpensive telescope, a digital camera, and a tripod for the camera and another tripod for the telescope. All that you need to do is to focus the telescope on a celestial object, such as a planet, and position the camera lens so it points into the eyepiece of the telescope. This is called an afocal coupling. Then, you can take all of the pictures that you want. Just remember that the earth is rotating and you will have to make periodic adjustments of the telescope and camera to compensate for this.
If you're convinced that you need a more elaborate set-up, then you'll need to add a rotating mount and a T-mount to your set. A T-mount is actually an adaptor that hooks your camera onto the telescope. The rotating mount is usually a motorized mount that basically moves with the earths rotation. An excellent rotating mount is the German-Equatorial Mount. This mount has a polar axis and a declination axis. The polar axis is aligned to the earth's axis of rotation by being aligned with the earth's North or South celestial pole. The declination axis moves at right angles to the polar axis. With a motor controlling both of the axes, any celestial object can be found. Once you have found the object you want, both axes lock up and only the polar axis is used to follow the object.
To take your astrophotography a step further, you might want to consider a GoTo computer-controlled telescope with a Global Positioning System (GPS). With this type of telescope, everything is computer controlled. The GPS in the scope automatically gives your physical coordinates, and aligns the telescope accordingly. After a few minor adjustments, you then program the information that you seek into the computer, and almost any celestial object can be found. Prices start at a few hundred dollars and up.
Astrophotography is not new, it has been around ever since John William Draper took a photo of the moon in 1840; and in 1880, John William's son Henry took a photo of the Orion Nebula. Today, astrophotography is a fast growing hobby. Whether you only have a simple set-up of an inexpensive camera and telescope, or you have a more elaborate expensive set-up, it's a very exciting experience to take good quality photographs of far away planets, galaxies, stars, and nebulas, or any other type of celestial objects.