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GB1164794A - A Improved Method and Apparatus for Controlling Photographic Exposures - Google Patents

A Improved Method and Apparatus for Controlling Photographic Exposures

Info

Publication number
GB1164794A
GB1164794A GB1710166A GB1710166A GB1164794A GB 1164794 A GB1164794 A GB 1164794A GB 1710166 A GB1710166 A GB 1710166A GB 1710166 A GB1710166 A GB 1710166A GB 1164794 A GB1164794 A GB 1164794A
Authority
GB
United Kingdom
Prior art keywords
capacitor
voltage
photo
exposure
image
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB1710166A
Inventor
Roy Walter Franklin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
H P LITTLEJOHN ELECTRONICS Ltd
Original Assignee
H P LITTLEJOHN ELECTRONICS Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by H P LITTLEJOHN ELECTRONICS Ltd filed Critical H P LITTLEJOHN ELECTRONICS Ltd
Priority to GB1710166A priority Critical patent/GB1164794A/en
Publication of GB1164794A publication Critical patent/GB1164794A/en
Expired legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03BAPPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/08Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
    • G03B7/081Analogue circuits
    • G03B7/083Analogue circuits for control of exposure time

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Control For Cameras (AREA)

Abstract

1,164,794. Photo-electric exposure control. H . P. LITTLEJOHN (ELECTRONICS) Ltd. April 17, 1967 [April 19, 1966], No.17101/66. Heading G1A. In an arrangement for controlling the exposure of a photographic emulsion to an image wherein a photo-transducer is exposed to the image, the object giving rise to the image, to the light source illuminating the object, or to the light reflected from or passing through the emulsion and the current passing through or generated by the photo-transducer effects the discharge of a capacitor to terminate the exposure when the voltage across the capacitor falls to a predetermined value; the voltage across the capacitor effects actuation through a virtual earth operational inverting amplifier having a high resistance input. The voltage may be displayed on a meter calibrated in exposure units and density and a number of range changing capacitors may be switched. The capacitor circuit may include means whereby the cell current is independent of the voltage across the capacitor or a junction generator to give a logarithmic time scale. Additional currents may be fed to the capacitor during reset to allow for factors such as film speed half-tone screen density, and lens aperture. The apparatus may include an additional portable photo-cell to read incident light at the film plane or to serve as a densitometer in order to assist in setting up.
GB1710166A 1966-04-19 1966-04-19 A Improved Method and Apparatus for Controlling Photographic Exposures Expired GB1164794A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1710166A GB1164794A (en) 1966-04-19 1966-04-19 A Improved Method and Apparatus for Controlling Photographic Exposures

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1710166A GB1164794A (en) 1966-04-19 1966-04-19 A Improved Method and Apparatus for Controlling Photographic Exposures

Publications (1)

Publication Number Publication Date
GB1164794A true GB1164794A (en) 1969-09-24

Family

ID=10089273

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1710166A Expired GB1164794A (en) 1966-04-19 1966-04-19 A Improved Method and Apparatus for Controlling Photographic Exposures

Country Status (1)

Country Link
GB (1) GB1164794A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4350438A (en) 1976-06-03 1982-09-21 Hoechst Aktiengesellschaft Light dosing device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4350438A (en) 1976-06-03 1982-09-21 Hoechst Aktiengesellschaft Light dosing device

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees