FIELD CAMERA (Fr., Chambre de touriste, Chambre de voyage, Chambre portative ; Ger., Reisekamera, Landschafts-kamera) Field cameras are necessarily designed to obtain the maximum of compactness and the minimum of weight consistent with steadiness.
Since they will be more exposed to atmospheric and climatic influences than indoor cameras, the workmanship must be good, and the wood of excellent quality and well seasoned. Rigidity is of great importance. When extended, there should be no shake or looseness at either front or back if grasped firmly with the two hands. The choice of pattern depends somewhat on the nature of the work to be undertaken.
For technical, engineering, and suchlike pur poses, a square bellows camera of somewhat heavy construction is usually preferred. Illus tration A shows an apparatus which can be used in the studio or on a tripod outdoors. The rigid front is suited for carrying heavy lenses, while the bellows racks backwards from the front, a useful movement in wide-angle work, where part of the image is sometimes liable to be cut off by the projecting baseboard of the ordinary type of camera. The back focusing movement is also valuable in photographing small objects at close quarters. The baseboard folds over the focusing screen when closed, thus preventing it from getting broken.
A lighter, yet still substantial, type of camera, suitable for general work out of doors, is illus trated at B. The swing front is useful when photographing high buildings, and a sufficient amount of rise is also provided for. The back,
which can be swung either horizontally or vertic ally, is arranged to slide close up to the front if desired, for use with wide-angle lenses. A well-known camera, noted for its great range of movement and particularly adapted for archi tectural photography, is shown at C. The back and front may be swung in every imaginable position with ease, and at once rigidly clamped or locked. The extreme high rise of front will be noticed. The front not only rises and falls by rack and pinion, but may be moved horizon tally or diagonally by means of a compound sliding and revolving device.
A representative example of a moderate priced triple-extension camera is illustrated at D. A triple extension allows the bellows to be racked out to about three times the focal length of the average lens used with a camera of a given size, and is an invaluable feature when using long focus lenses.
The cameras above mentioned are illustrative of the chief tendencies of design in modern field apparatus. A notable advance is shown on earlier ideals of construction, especially with regard to lightness, compactness, and the pro vision of mechanical conveniences. Double book-form dark slides are usually preferred with field cameras, and they should work without either stiffness or looseness. (See also " Camera," "Dark-slide," etc.)