GB1043622A - Photographic or cinematographic cameras having exposure meters - Google Patents

Abstract

1,043,622. Cameras; exposure control systems. VEB PENTACON DRESDEN KAMERAUND KINOWERKE. March 11, 1964, No. 10275/64. Headings G2A and G2E. The diaphragm aperture 15 of a still or cine camera is controlled by the moving coil of a photoelectric exposure meter 21, the coil being placed in a diagonal branch of a Wheatstone bridge and having no spring return means, a short circuiting switch 28 being placed across the coil and coupled to the shutter release 29. When release 29 is depressed, battery 26 is connected to the circuit by switch 27 and the coupled switch 28 is opened; light flap 34 is pivoted away from aperture 18 and the bridge is unbalanced by the resulting charge in the resistance of cell 19. The apertures 15, 18 are then set by the resulting deflection of the moving coil which controls blades 11, 12, pivoted on shafts 9, 10, through pin 22 and slot 20. When release 29 is raised switch 28 is closed and the galvanometer is short-circuited and cannot deflect if the camera is jolted and the battery is simultaneously switched off. Film sensitivity is allowed for when disc 30 is rotated by push rod 32 with pawl 33 to control the amount of light incident on cell 19 by means of a selected diaphragm 31. Exposure meter lens 5 and objective lenses 3, 4 are adjusted by a common setting rod 6. Beam-splitter 7 directs light to the view-finder by way of mirror 8.