Early photographers relied on their tripods as the old films were so insensitive, and required such long exposure times, that it was impossible to hold the camera steady. The advent of sensitive film and digital cameras makes acceptable results from hand held shots common. Forms of image stabilization, or vibration reduction, are becoming more common in lenses and cameras bodies.
While these advances make it easier to get good results hand holding the camera, for the very best, sharpest, clearest images a tripod is still a valuable tool. A good tripod all but eliminates camera shake, except for wind and vibration from the mirror.
How can they aid composition? Because a tripod holds the camera in the same position, this forces the photographer to think more about the best camera position. The tripod make sit easy for small adjustments to the camera position and angle that may take several minutes. This also ensures that experiments with different settings or techniques are all variations of the same shot.
The other common support device is a tripod with one leg, or a monopod. These are the favorites of sports photographers, even those using Canon and Nikon professional lens with built in image stabilization. Using a monopod allows the photographer more freedom to choose a slower shutter speed to suit the action, with less emphasis on avoiding camera shake.
A monopod is also lighter and easier to move around than a tripod, making setting up a shot quicker, this is important in fast paced sports environment. Sports events can go all day and it is easier having a monopod to support the camera and a long lens. The monopod also makes carrying everything around easier, as you can balance the monopod on your shoulder with the camera attached. In some locations, tripods are not allowed. However, a monopod is not a not a tripod so it can help to get by some petty regulations and restrictions.
On the top of a tripod or monopod is the head. The head connects the pod to the camera and incorporates devices for aiming the camera.
Although it is possible to screw the pod directly into the base of the camera, the preferred method is a quick release plate. The plate screws into the base of the camera and then the plate fits into receptacle in the head and secures with a lever operated locking mechanism. The camera can be attached or and removed in a second
Long lenses usually attach to the pod using a collar in the same manner as the camera body. This provides better balance, making it easier to aim the camera and reducing the tendency of the lens to drop at the front.
There are two basic types of head, ball, and pan and tilt. Ball heads are more flexible as the camera can aim at any angle, locking in position with one control. Pan and tilt heads have separate horizontal and vertical adjustments. This makes them slower to use, although they are good for architecture shots where precise horizontal or vertical adjustments are nequired.
The main necessity for all types is strength and rigidity, although this often can impose a weight penalty. Carbon fiber is a popular material for top line pods as it combines light weight with high rigidity. A good aluminum pod though will perform just as well but may weight a bit more.
When choosing a pod make sure the legs are long enough so you do not have to bend over to use the camera. This should be without using wind up central posts, as they tend to be more unstable as they go higher.