GB785857A - A device for indicating depth of focus in photographic cameras - Google Patents

Abstract

785,857. Photographic cameras. DECKEL, H., and DECKEL, F. W. Jan. 10, 1956 [Feb. 10, 1955], No. 839/56. Class 98(1) Means for indicating the depth of focus in a photographic camera include two indicating elements each movable by a pivoted lever, the levers being controlled by a common driving element through a cam slot from the lens diaphragm setting element. As shown in Fig. 1, rings 16, 18 carrying pointers 10, 12 which move over a scale of distance 14 are coupled to move equally in opposite directions, A lever 22, pivoted to a pin 26 carried by a fixed ring 28, has a pin 32 engaging a slot 36 in the ring 18. A lever 20 pivoted at 24 to the ring 28, has a pin 38 extending through a slot 42 in lever 22, and a pin 30 entering a slot 34 in the ring 16. The pin 38 enters a cam slot 46 on a ring 48 connected to the diaphragm setting member. When the diaphragm is set, the movement of ring 48 transmitted through the cam slot 46 and pin 38 to the levers 22, 20, causes the rings 16, 18, and their pointers 10, 12 to move equally in opposite direction to indicate on scale 14 the nearer and further limits of the field of definition. A system is described wherein the depth of focus indicator is incorporated in an interchangeable objective, the focusing scale and the diaphragm setting scale being mounted on the lens mount, and the shutter setting scale, to which the diaphragm scales may be detachably connected, being mounted on the camera bodies.