One of the most interesting things I've discovered in recent years is that tripods can be configured differently depending on what it is you actually want to do and the key to doing this is having the right head so without further ado here is a quick overview of some of the most common types of heads that are available for still photography.
- 3-way Head. This is about as basic as it gets and for the first several years that I had a camera this is what I associated with a tripod. They pan they tilt and they rotate. Each axis has to be locked and unlocked individually. Because each axis is independent they are both somewhat slow to operate and fairly precise. This is a good choice for general use.
- Ball Head. Also extremely common but usually slightly more expensive the ball head is designed for rapid operation. Using a single knob the user is able to unlock all three axis at once. Quality ball heads are capable of going into a semi-locked state where the user is able to move the camera but the camera will not move on its own eliminating the need to use the locking mechanism at all after the tension is set. This head is also a good choice for general use. Pistol grip heads also fall into this category.
- Geared head. These heads are known for their extremely precise movements and have a place in architecture photography. They are most similar to three way heads but instead of or in some cases in addition to unlocking (depending on the head) they use a screw mechanism to advance by small degrees.
- Gimbal Head. Also known as Wimberly heads these heads place the camera's center of gravity below the axis of rotation. These types of heads are most commonly used to support extremely large lenses. The advantage of a Gimbal head is that even when it is unlocked the camera is completely stable and the camera feels nearly weightless and even if the user were to let go of the camera it would simply return to a horizontal position. Sports and birding are the most common applications of these types of heads.
- Panoramic heads. There are a number of different types of panoramic heads from simple ones that will help you to create a single row of precisely aligned images to complex motorized ones that will automatically create a full sphere of stitchable photos. The key difference between a true panoramic head and a head that just rotates is that a panoramic head will allow you to place the camera at its optical center also known as the nodal point thereby preventing an effect known as parallax error.
While most heads can be pressed into service to do whatever kind of photography you might want to do having the right one on hand can make the difference between getting the shot and not.