TYPES OF PHOTOGRAPHIC CAMERA There are two principal kinds of photographic camera, studio and field, the former type a comparatively small category almost exclusively used by professional portraitists. The studio camera forms as a rule part of a combina tion (fig. 19), in which a sub stantially built stand, capable of adjustment as to height and inclination, is included. Such a combination should be movable to any part of the studio, prefer ably on casters. The camera is fitted with square bellows and fo cussing is by a double rack and pinion movement, sometimes sup plemented by a draw-out exten sion for quickly obtaining a coarse focus. Extra rigidity is given to the fully extended instrument by a wooden centre frame. The front has a rising and falling movement and is very solidly built to carry large and heavy por trait lenses. In many cameras of this type there is an internal flap shutter which can be worked noiselessly by a bulb. Prior to recent changes which have greatly modified the appearance of both, the main difference between a studio and a field camera lay in the back arrangement.
Field cameras are of many sorts and sizes and include several classes to which separate attention is being given. But the descrip tion "field" may be said to belong properly to the kind of camera used in the open, and on a stand, for general work which is not ordinarily attempted in the studio, such as large groups and genre studies in natural surroundings, as well as architecture and land scapes. Such a camera must be reasonably portable if plates of a fair size have to be exposed, and it should possess, in addition to a swing back (or front) and a rising and falling front, an exten sion sufficiently variable to enable lenses of relatively long or short focus to be used. Thus a half-plate camera, the lens normally employed with which would probably have a focal length of 8 in., should have a full extension of not less than 16 in. and it should be possible to rack it in to take wide-angle lenses with a focal length of not more than 4 in. As it is essential that a field
camera should be quite rigid when fully extended the design of an instrument possessing this qualification, in addition to that of portability, presents some difficulties.
The "square-form" camera equipped with parallel bellows re mains a favourite with many for field work, owing to its rigidity and adaptability to all classes of subjects and all types of lens. Only moderate portability, however, is possible with this model, and a rather substantial tripod is needed to support it at all satisfactorily. For sizes above half-plate, accordingly, a lighter form of camera with conical bellows is frequently preferred, and, provided that the design is good, and the material and workmanship all they should be, a field camera on these lines will meet all requirements. Formerly, only a well made conical bel lows camera would carry a variable telephoto lens without risk of vibration ; today many designs are offered which eliminate or diminish this hazard. Some conical bellows models have base boards in which a circle has been cut out and a metal ring inserted, thus constituting a tripod head to which ordinary tripod legs can be attached.
Owing to improved facilities for enlargement field cameras in the larger sizes are not now so freely used as formerly, and the convenience of roll film has rendered diminutive Kodaks, Car bines and other "pocket" instruments increasingly popular. But there is an intermediate type which, as an efficient compromise, is perhaps the most useful form of camera in existence. This is well known as a "view camera" having all the features of both studio and field types. This is also known as the "hand or stand" variety. Following Wat son's "Alpha" the productions of Newman and Guardia, which owe their perfection chiefly to the mechanical genius of A. S. Newman, and those of Adams, the Houghton-Butcher Co., Erne mann and other makers, are mod ern examples of "hand or stand" design in which every conceiv able requirement is met.