GB455774A - Improvements in means for determining the correct exposure in photographic apparatus - Google Patents

Abstract

455,774. Photographic exposure meters. RISZDORFER, O., 1, Gellerthegy - utca, Ungarn, Budapest. March 18, 1935, No. 13413/36. Convention date, March 16, 1934. Divided out of 453,845. [Class 98 (i)] In a photo-electric meter, the amount of light falling on the cell is regulated by the diaphragm of the objective lens, and the electrical current of the cell is regulated in accordance with at least one other variable factor. The cell 62, Fig. 1, is mounted behind the objective lens 59 on a shaft 70, the bent end 71 of which is connected with the shutter release lever 61. A contact on the shutterspeed disc 60 moves over a resistance 57 in the circuit of the photo-electric cell, which also includes a measuring instrument coil 65 with a pointer 66. In determining the exposure, the shutter speed is regulated until the pointer 66 is restored to its zero position, and upon actuation of the release lever, the cell 62 is swung away from the lens axis. In the form shown in Fig. 3, the shutter speed control is connected to a ring 80 which has a wedgeshaped member engaging a stop 79 to vary the inclination of a series of adjustable flaps 75 in front of the cell. The flaps are pivoted on the framework 73 of the cell by rotatable pivots, the extensions 76 of which are connected to an adjustable ring 77 bearing the stop 79. The photo-electric cell and control device are fixed on a shaft 84 so that they can be swung out of position. In the form shown in Fig. 5, the photo-electric cell is made in two halves 88, 89, mounted on a shaft 90 and connected to the shutter-speed ring 94 by connecting rods 92, 93. The adjusting ring 96 engages the ring 94 by a wedge-shaped peg 95 so that the inclination of the cells can be adjusted. Other factors influencing exposure can be taken into account by applying light filters.