GB877537A - Photographic camera with coupled photoelectric exposure meter - Google Patents

Abstract

877,537. Photographic cameras. ZEISS IKON A. G. Nov. 29, 1957 [Nov. 30, 1956; March 6, 1957; March 23, 1957], No. 37336/57. Class 98(1). In a photographic camera having a built-in exposure meter and a cam and follower mounted in the objective housing for mechanically transmitting a measure of the deflection of the meter pointer to a diaphragm aperture and / or shutter speed adjusting member, the cam is so shaped as to compensate for the non-linearity of the relationship between the diaphragm or shutter speed scale and the response of the meter to the incident light. As shown, the diaphragm is controlled by two independently rotatable rings 21, 22, one 22 being coupled to follower 4 of photoelectric exposure meter 1 and the other 21 to shutter speed setting ring 15 which carries index 16 indicating the shutter speed on fixed ring 17 and the diaphragm aperture on ring 23. Manual adjustment of ring 23 turns ring 22 and ring 25 which is coupled to ring 23 by a tooth on member 29 resiliently urged into engagement with one of a number of notches 32 in ring 23. On disengagement, rings 23, 25 are relatively rotatable to set the film speed against mark 27. The film speed may alternatively be allowed for by means of an adjustable diaphragm mounted in front of the photo-cell. The form of engagement between the leg 47 of member 29 and the cam 8 differs with the mounting of the lens. When the lens is both interchangeable and axially displaceable for focusing an axial slot is provided in the cylindrical part of cam 8 and the leg is resiliently engaged therein (Fig. 3b, not shown). When the lens is not interchangeable but is displaceable, leg 47 extends non-resiliently through aperture 42. When only the front cell of the lens is displaceable, the leg resiliently engages a notch in a flange attached to cam 8 (Fig. 1, not shown). Alternatively, the cam 8 or the cam 8 and sliding rod 6 can be mounted so as to be interchangeable with the lens mount knurled wheel 37 having toothed gear 38 meshing with toothed segment 39 on cam 8 may be provided and may be the sole means for turning ring 23. Alternatively, gear 38 may turn ring 23 directly. A range scale 48 is provided. The exposure meter pointer may move over an exposure value scale or such a scale may be provided on the lens mount. The pointers of the exposure meter may be visible in the camera view finder. Numbered index positions for filter factors may be provided adjacent mark 27 on ring 23 (Fig. 7, not shown) and a film type and speed indicator mounted on the camera casing (Fig. 6, not shown). Specification 839,332 is referred to.