Hand Cameras are small compact varieties of cameras which are intended to be held in the hand during the taking of the photograph. They are therefore chiefly adapted for short or "instantaneous" exposures. In the majority of instruments there is no arrangement for "focussing," as a short focus lens is employed and so fixed that all objects beyond about five yards will be practically in focus. Most are adapted for taking photographs of quarter-plate size, and are supplied with arrangements by which a number of plates can be held and photographs successively taken without the necessity of opening the camera to change the plates. Some are fitted with continuous "films" (q.v.), so that 50 or more pictures can be obtained before changing. They are therefore very useful for touring purposes, where the weight of the ordinary form is objectionable, and for photography in places where the setting up of a tripod stand, etc., would be an impossibility. The hand- or detective-camera has within recent years become extremely popular, anrl to meet the growing demand very large numbers of different forms exist. in the market, differing chiefly only in their constructive details.