User:Farski/Tripod head

A tripod head is the part of a tripod system that attaches the supported device (such as a camera) to the tripod legs, and allows the orientation of the device to be manipulated or locked down. Modular or stand-alone tripod heads can be used on a wide range of tripods, allowing the user choose which type of head best suits their needs. Integrated heads are built directly onto the tripod legs, reducing the cost of the tripod system.

The main function of any tripod head is to provide the ability to hold the attached device fixed in a specific orientation until the user needs to change it's position. In the case of a photographic camera, this can help reduce vibration that would appear when using relatively slow shutter speeds while still being able to quickly recompose for another shot, or allow for very long exposures. In cinematography or video applications, a tripod head allows the camera operator to pan and tilt with much more control that compared to hand-holding the camera.

The various types of tripod heads available provide different control mechanisms and have distinct applications. Some can restrict movement to a single axis, while others offer robotic movement to increase the precision of the movements. The materials used to construct tripod heads and the physical designs of various heads can be drastically different, depending on their intended use.

In some situations a tripod head may be used without a set of tripod legs. Heads can be attached to monopods to provide more versatility, or to a simple plate with a base mount for when the height of a full tripod is unnecessary.

Base mounts
The base mount is the connection between the tripod head and the tripod legs. Often the head will have a fairly large, flat base that sits on top of the tripod, and uses cork or rubber to increase the friction between the two, to prevent the head from unscrewing off during use. The actual connection between the two is often made with a screw. A common standard for base mounts on photographic tripod equipment is a 3/8-16 screw on the tripod head (a screw that is 3/8 inches in diameter, with 16 threads per inch) and a matching receptacle on the tripod. Tripods intended for smaller photographic equipment that do not need to be a rugged (such as point and shoot cameras or smartphones) use a smaller 1/4-20 screw.

Head mounts
The head mount is the point where the device attaches to the tripod head. Most camera equipment includes a built-in 1/4-20 receptacle, so the majority of tripod heads utilize a 1/4-20 screw as their head mounts. Many consumer level tripod heads use the bare head mount to attach the camera, but higher end models often include a camera mounting system that is pre-attached to the head mount.

Camera mount
Camera mounting systems are used to make attaching and detaching devices to the tripod quicker and easier. Many mounting systems are called "quick-release" systems, and utilize a two-piece mechanism. One piece is a plate that is affixed to the underside of the device, and the other piece is a receiver (normally mounted to the tripod head's head mount) that is specifically designed to hold the plate. This is often achieved with a groove or a taper on the plate, and a locking release on the receiver that allows for quick removal of the device.

Arca-Swiss style
Camera equipment maker Arca-Swiss independently developed a quick-release system for use on their tripod heads. It is based on plates that are 38mm wide, and have a 45° dovetail, which is held into place on the receiver with a screw clamp. Starting in the 1990s, with the popularization of the Arca-Swiss B-1 ballhead, many other companies began creating producing plates and including Arca-Swiss style receivers on their tripod heads. Many manufacturers now utilize this system, including Acratech, Arca-Swiss, Giottos, Kirk Photo, Really Right Stuff, Wimberly, and others. Today most plates are machined aluminum are attached to the cameras or lenses with a 1/4-20 hex screw.

Another aspect of the Arca-Swiss system is that the mounting plates are designed to prevent accidental rotation of the plate relative to the device. When used with a camera or camera body the plates incorporate an anti-rotation flange or lip. When mounted to a lens with a foot, the plate will often be secure with two screws to prevent rotation. When this type of system is used, the camera cannot become accidentally detached from the tripod, which is possible when using a quick-release system that doesn't prevent rotation, or when no camera mount is used. Nearly all makes and models of modern SLRs, medium format cameras, and large lenses have specific plates available with anti-rotation flanges. There are plates available for certain models of other formats of cameras, such as point and shoots, as well. Universal mounting plates are also available, which can be used with nearly any camera with a tripod mount, though they provide no, or very little, anti-rotation protection.

Some plates and receivers implement further failsafes. In the event that the receiver clamp is loosened slightly, it is possible the plate would be able slide out of the receiver completely. To prevent this, grooves are added to the receiver and small protrusions (stops) are added to the plate (often in the form of small screws, so that they are removable). Even if the clamp should loosen, the stops would limit the movement of the plate to only within the grooves, preventing a complete disconnect, and often equipment damage.

Ballheads
A ballhead uses a ball and socket type joint for orientation control. The ball sits in a socket, which can be tightened to lock the ball in place. A stem extends from the ball which terminates at the head mount. They tend to have fewer parts than other types of tripod heads due to their simple mechanism, but the parts must be precisely machined to fit well together and provide smooth movement, increasing their average price. Balheads offer the convenience of simple controls, but are lacking in terms of precise movements, making specific alignment and image positioning a challenge.

The most basic ballheads offer a single control, a tension control, which is used to tighten or loosen the joint and prevent or allow movement of the attached device. Higher end heads may offer additional controls. Some have independent panning control, which allow the entire joint mechanism to be rotated horizontally 360°, while maintaining the orientation of the ball joint. Other ballheads include an additional control on the joint, called a drag control. This allows the user to set a secondary tension level on the ball, based on the current load, to hold the attached device in place when the tension control is disengaged, while still allowing explicit movements.

Panheads
A panhead is a tripod head that has independent controls for each axis. Movement along each axis can be locked or unlock without affecting the others, and most panheads offer allow for movement long 3, 4, or 5 axis. The flexibility this affords can make leveling a device or taking single-axis panoramas very easy. Panheads generally use long handles for their controls, and tend to have more moving parts than a ball head.

Panoramic Heads
Panoramic heads generally only allow for movement along a single axis: the horizontal axis. They are intended to be used to capture a sequence of images at various angles along that axis, which will later be stitched together digitally into a single image to form a panorama. Panoramic heads often include indexing in the mechanism or precise printed scales on the head to aid in the process of capturing many images.

There are also robotic panoramic heads which can be programmed with motion control instructions. The robotic head will move in steps through a range of angles, and can automatically trigger the camera to take a photo (or photos) at each step. Because of the precision gained through the use of a machine, these heads can be programmed to move along two axis, allowing the resulting panoramas to be stitched in two dimensions. Robotic heads can also be used with time-lapse photography, providing some movement of the scene over the course of the time lapse.

Panoramic heads are often used in conjunction with a nodal rail, allowing the nodal point of the camera to be directly over the point of rotation. This can produce better or more natural results during the stitching process. Both manual and robotic panoramic heads can also be used to create HDR panoramas.

Gimbal Heads
Gimbal heads are designed mainly for long, heavy telephoto lenes, and are often used for wildlife or sports photography. Their primary feature is the ability to balance the camera and lens within the tripod head and use tension controls to simulate a "weightlessness", where the camera can be moved freely, but stays in place when not being moved. They allow for easy tracking along the vertical and horizontal axis, but generally do not offer the ability to make precise angular movements along either. A gimbal head excels at tracking a fast moving subject, and allowing large, cumbersome camera setups to be used with more agility than nearly any other support system.

Fluid Heads
Fluid heads are the dominant tripod heads in any motion picture industry. They provide extremely smooth free movement, even with the heaviest of cinema or television cameras. The fluid reduces the risk of the camera operator introducing any jerkiness or vibration to the shot during a pan or tilt through dampening, and also reduces the friction between moving parts of the head. As the size of high quality video cameras has become greatly reduced, there are now fluid heads designed even for camcorders, which are being used increasingly in production environments.