GB1255150A - A camera and a method of exposure control - Google Patents

Abstract

1,255,150. Photographic cameras. K. LECZKOWSKI. Dec.24, 1968, No.61511/68. Heading G2A. A photographic camera has an exposure control system which senses ambient light intensity and sets the camera accordingly for a subsequent daylight exposure and a flash-light exposure control which sets the camera for a subsequent exposure by flash-light according to the range of the object to be flash-light illuminated, one of the systems being capable of setting the camera without altering the diaphragm aperature so that the camera can be used for photographing a scene illuminated by a mixture of day light and flashlight since the camera can be set for both types of light without the setting of said one system disturbing the aperture needed for the other system. In one embodiment, a distance adjustment ring 1 carries foreground distance markings 2 and co-operates with a locking lever 3. The ring 1 can be coupled by a catch 8 with a diaphragm adjusting ring 4 for setting correct film sensitivity according to a scale 7. Ring 4 has a diaphragm scale 5 co-operating with a fixed mark. Clockwise rotation of ring 1 and ring 4 is effected by a spring 16. In operation, the foreground distance is adjusted on ring 1 which through ring 4 sets the appropriate diaphragm. A daylight automatic control system adjusts the shutter speed to suit this aperture. The shutter is then released to make an exposure of foreground and back ground. The shutter in running home or back to its shut position unlocks lever 3 and allows spring 16 to reset the ring 1 and simultaneously opens the contacts 12 previously closed by a lever 11. In another embodiment, Fig. 3 (not shown) a fixed diaphragm of "f8" is used. In this case, the foreground distance setting adjusts the flash-light intensity by means of a switch arm (40) engageable with push buttons (41) to (44) which determine the flash intensity. In a further embodiment, Fig. 4 (not shown) flash-light exposure is controlled by both diaphragm regulation and flash intensity. In a similar embodiment, Fig. 6, the diaphragm ring 81 is external of a distance ring 84, the rings 81 and 84 being connected by a spring coupling (86) Fig. 5 (not shown) engaging indentations of a flash index scale (87) of ring 81. A focusing ring 89 has a sleeve 93 provided with a cam slot 94 engaged by guide pins 97 projecting from an objective sleeve 96 slidable along the optical axis. Adjustment of ring 89 adjusts the depth of field and diaphragm for a flash exposure. A coupling 99 is disengaged for daylight exposure, but is maintained for mixed light exposures. Exchange objectives carried by a sleeve (113) Fig. 10 (not shown) may be fitted in a similar embodiment. In a further embodiment similar to Fig. 4 (not shown) a switch arm 263 Fig. 12 corresponds to switch arm (63) Fig. 4 (not shown). A contact 264 connects capacitors 221 to 225 in parallel in circuit with a flash-bulb 208. In operation, the diaphragm, adjusting ring (51) Fig. 4 (not shown) is adjusted such that contact 264 closes contacts 211, 212 and 213 to switch in capacitors 221, 222 and 223 to produce a flash-light exposure appropriate to the distance set. Similarly, flash duration may be shortened according to the distance set Fig. 13 (not shown) by varying resistors included in an R. C. circuit, or by selecting the number of flash-lamps (271 to 275) Fig. 14 (not shown). The lamps are carried by a reflective strip fed through a unit (220) so that the required number of unused lamps are in the unit.