VIEW METER (Pr., Chercheur, Icononatre Ger., Bildmesser) A device for showing the amount of subject which would he included on the plate if the camera were set up in a given position, thus enabling the operator to judge the best point of view without experimentally erecting the appara tus. One pattern is like a small telescope with a suitable mask or opening inserted to limit the view to the required proportions. Another form consists of a small rectangular frame sliding on a graduated rod, at the other end of which is a sight. (See the illustration.) The opening should be proportional to the size of plate to be used, while the distance from the sight to the opening should bear the same proportion to the focal length of the lens. Thus, for a quarter-plate camera with a lens of 6-in. focal length, the open ing might be 2+ in. by if in. and the distance of the sight 3 in. On applying the eye to the sight, the view seen through the opening is then exactly identical with that which would be included if the camera were set up with its lens in the posi tion of the sight and pointing in the same direction. Such a view meter is readily made
to fold up when not in use, and may be carried in the pocket.
By marking different distances on the rod, the finder may be made to show the view included by lenses of various focal lengths. Thus, in the foregoing example, if the frame is slid along the rod until it is 2 in. from the opening, it gives the same amount of view as a 4-in. focus lens, and so on. The open frame gives the clearest view ; but, if preferred, a piece of blue glass may be fixed in or against the opening, when the subject is seen in monochrome and its photographic value is more easily judged.