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No matter how good a camera may be, or how accurately it has been made, it cannot yield really acceptable results if it moves during the exposure. Much of the poor definition obtained by amateur and professional photographers is caused by camera shake during the time the shutter is open.
At shutter speeds slower than 1/25 second some sort of camera support is always essential. A tripod is undoubtedly the most effective answer tp camera shake and should be used wherever possible; certainly whenever top quality results are required.
A tripod is a three-legged stand on the top of which the camera is fixed. Except for some of the larger studio models most tripods have folding or telescopic legs. There is nothing to beat the heavy wooden tripod for strength and rigidity. It is ideal for studio and indoor use but it is rather cumbersome to carry around and for this reason it is no longer popular with modern photographers who like to travel light. The necessity for portability has led to the lighter, collapsible type of tripod. Many of these are excellent, but some of the cheaper models are unsteady and useless.
The light folding type of tripod is not suitable for a heavy plate camera. A heavy camera needs a heavy tripod; there are even people who prefer to use a heavy tripod with a small camera rather than risk camera shake.
Methods for altering the height of a tripod vary according to the type being used. With a telescopic tripod it is only necessary to slide a section of the tubing in or out until it reaches the correct height. Folding tripods can be adjusted similarly by unfolding the legs to the height required. The permanent, studio types of tripod and some of the better metal types have an adjustable centre pillar.
The simplest type of stand consists of a solid, heavy base carrying a vertical pillar with a platform on top to take the camera. The centre pillar is adjustable for height and the platform can be tilted to point the camera up or down. In the more expensive versions of such stands all the movements are controlled by wheel or handle operated screws. One handle raises or lowers the pillar, another turns it to rotate the camera in the horizontal plane and a third controls the tilt of the top. The base of the stand may be on wheels with provision for locking them or putting them out of action when required.
A stand built for heavier duty consists of two vertical pillars mounted on a heavy low trolley. The camera is carried on a counterbalanced tilting platform between the two pillars. This type of stand has the advantage of allowing the camera height to be adjusted from the top of the pillars (which may be 7 or 8 feet high) down almost to ground level.
An even more elaborate type of camera stand is used in many commercial studios. This is the "all-angle" stand. It consists of a rigid H-section alloy chassis mounted on wheels. The chassis is designed to hold a large-diameter tubular column which carries the camera platform. The column is supported in a universally-mounted housing which allows it to be swung to any angle, and extended or rotated by control handwheels. Separate controls below the camera platform allow the head to be tilted hi two planes. This type of stand is also used for clinical photography in hospitals where it allows the camera to be supported over the top of a prone patient at any angle. The stand is mounted on large castors which can be raised out of contact with the floor when once the camera is in position.
The camera must be attached firmly to the tripod or stand, and although there is always a plate or table with an attaching screw, this is not always satisfactory as it does not allow the camera to be set at an angle to the horizontal. The two most popular tripod heads, designed to allow adjustment of the camera angle, are the "universal" ball and socket head, and the pan and tilt head.
The ball and socket head, as its name suggests, is a ball with a tripod screw on top which can turn freely in a socket. A clamp can be tightened to grip the ball firmly in any position. This allows the camera to be tilted or angled as the user wishes.
Pan and tilt heads provide the same range of movements but are rather more versatile. They are primarily intended for cinematography and can be locked so as to swing (or "pan") horizontally but not vertically. This movement is impossible to achieve satisfactorily with a simple ball and socket head but it is essential for a cine camera to be able to scan a scene horizontally without any trace of wobble.
The panoramic head is basically the same as the pan and tilt head except that the axis of the panning mechanism has a scale engraved around it. This is calibrated in degrees from 0 to 360 and either moves with the head or is fixed on the stationary part. Panning of the camera can then be measured in degrees against a suitable reference mark engraved on the head. This is invaluable for photographing a panorama in sections when, after each successive exposure, the camera is panned to a fresh position. The angle through which the camera must be moved each time is equal to the angle of field of the lens (in practice, slightly less).
Other tripod heads are made for specialized subjects. The stereo head provides two alternate positions for the camera with a separation of 2 1/2 inches. for taking stereo pairs for three dimensional viewing. For astronomical photography there is the equatorial head which when driven by a special clock, keeps the camera following stars during time exposures. Another type of head available, particularly for twin lens reflex cameras, is designed to overcome parallax errors in sighting the camera; it allows the camera to be slid upwards, on a tube, to the exact height necessary to compensate for the parallax. This height is normally preset.
A special type of tilting head is useful for certain subjects such as still-life close-ups, copying, etc., taken with a heavy camera. The head there consists of two wooden platforms hinged book fashion at one end, and fitted with adjustable struts at the other to open the two halves to the desired extent. The bottom half is mounted on the tripod and the top carries the camera. The more the two halves are opened out, the greater the tilt; usually the adjustment possible is from 0° to 90°. Although this type of head permits tilting in only one direction, it is considerably firmer than a ball and socket or other type of tilting head.
To reduce the waste of time over fitting a camera to the top of the tripod by the normal screw, some camera makers supply a quick action holder for use with their own cameras. The holder has a tripod bush which allows it to be fitted onto the tripod head in place of the camera in the normal manner. With the holder in position the camera can be mounted on the tripod or removed from it in a second or two. The actual method of securing the camera body depends on the make of camera and most quick-release attachments have to be designed for a specific camera and cannot be used with other makes. However, universal quick-release fittings use an attachment on the camera (screwing into the tripod bush) which mates with a fitting on the tripod.
When the camera has to be supported on a moving base (e.g. on a vehicle moving over a rough surface, on a boat or in rocket-borne equipment) it may be mounted on a gyro-stabilized platform. This is essentially a camera support housing a spinning gyroscope driven by compressed air or electricity. The whole assembly is slung in gimbals which leave it free to turn in both horizontal and vertical planes. When the gyroscope is spinning, the support is held "straight and level" no matter how the carrier changes its altitude or direction. Simple versions use the gyroscope mounting merely to increase the camera inertia and so smooth vibrations and reduce camera shake. Alternatively, the gyro may be mounted separately and be used merely for feeding stabilizing signals to the control system of the entire vehicle in which the camera is carried.
In motion picture studios, the gyroscopic effect is applied to the camera support for another purpose. A gyroscope is mounted in the tripod panning head with its axis horizontal. When the gyroscope is spinning it opposes the panning movement of the head with a force proportional to the rate of turning- i.e: the faster the operator tries to move the head, the greater the resistance he has to overcome. The result is that the panning motion can be started, held steady or stopped smoothly and without sudden jerks or changes of speed.
A similar damping effect is obtained by incorporating an escapement gear with flywheel into the tripod head. The gear is coupled with the panning or tilting movement (or both) and is directly driven by the manual effort of moving the camera on the tripod.
A camera clamp can be a very useful support when it is inconvenient to carry a tripod. It is simply a pair of metal jaws which can be fixed to solid objects such as a table or a fence with a screw to hold the camera. Most of them incorporate a "universal" fitting to point the camera at any angle.
The pistol grip provides a steady single-hand hold, which is useful on both still and cine cameras yielding shake-free negatives at exposures considerably longer than are possible with the conventionally hand-held camera. A built-in cable release enables the shutter to be released by means of a trigger on the grip. The pistol grip is not, of course, suitable for time exposures.
The monopod is a support consisting of a single leg which is used for keeping the camera still during slow exposures. Usually it is a telescopic tube which extends to about 5 feet. The camera is attached to the top and the foot has a spike or a rubber ferrule to stop it from slipping. Exposures of up to 1 second are usually quite safe.
The chestpod is a shortened variation of the monopod. It consists of a metal rod about 12 ins. long with a screw for the camera at one end and a leather strap at the other. The strap is then hung round the neck so that a downward pressure on the rod tautens it, and enables the camera to be held steady at eye level.
The gunpod is another light-weight portable support. As its name implies this is shaped like a rifle stock and fits comfortably into the shoulder. Many people use a gunpod to steady their cine cameras in the absence of a tripod and find it a reasonable substitute. This type of holder is also used for wild life photography with a miniature camera and a high-powered telephoto lens.
The chainpod is an extremely simple support that works quite well in practice. A piece of chain about 5 feet in length has a screw at one end which is fixed to the camera. The other end is then dropped on the ground and the user places his foot on it. By pressing the camera upwards the chain tautens and holds the camera steady. The chainpod can be used equally well with both eye-level or waist-level cameras.