GB1361392A – Photographic explosure controller
– Google Patents
GB1361392A – Photographic explosure controller
– Google Patents
Photographic explosure controller
Info
Publication number
GB1361392A
GB1361392A
GB4548370A
GB4548370A
GB1361392A
GB 1361392 A
GB1361392 A
GB 1361392A
GB 4548370 A
GB4548370 A
GB 4548370A
GB 4548370 A
GB4548370 A
GB 4548370A
GB 1361392 A
GB1361392 A
GB 1361392A
Authority
GB
United Kingdom
Prior art keywords
exposure
control
density
value
resistors
Prior art date
1970-09-24
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
GB4548370A
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.)
Individual
Original Assignee
Individual
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.)
1970-09-24
Filing date
1970-09-24
Publication date
1974-07-24
1970-09-24
Application filed by Individual
filed
Critical
Individual
1970-09-24
Priority to GB4548370A
priority
Critical
patent/GB1361392A/en
1971-09-17
Priority to US00181472A
priority
patent/US3732011A/en
1971-09-24
Priority to DE19712147801
priority
patent/DE2147801A1/en
1974-07-24
Publication of GB1361392A
publication
Critical
patent/GB1361392A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
Classifications
G—PHYSICS
G01—MEASURING; TESTING
G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
G01J1/00—Photometry, e.g. photographic exposure meter
G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
Abstract
1361392 Photographic exposure control C HANSARD 15 Sept 1971 [24 Sept 1970] 45483/70 Heading G2A Apparatus for controlling the exposure of a photo-sensitive material to light comprises a photo-cell 1 responsive to the intensity of light which controls a pulsing circuit 3 so that the frequency of the produced voltage pulses is dependent on the light intensity, a control resistor 5 manually adjustable in accordance with a given parameter through which the pulses are applied to a capacitor 6 which is manually adjustable to a predetermined value corresponding to the quantity of light needed for a desired exposure of the material, manually operable switching means to initiate exposure of the material to light and simultaneously to commence charging of the capacitor through the control resistor by the pulses, and trigger means 10 operative to stop the exposure when the charge in the capacitor reaches a predetermined value. The apparatus is used to control both the main and the flash exposure in a process camera, alternatively it may be used to control the exposure in a contact printing box. In using the apparatus to make a half tone negative, the apparatus has, in addition to photocell 1 controlling the main exposure, a photo-cell 11 controlling the flash exposure, the exposures being made successively via change-over switches 9, 17. For both exposures, the width of the rectangular pulses are controlled by selection of resistors 4a, 14a forming part of pulse shaping circuits 4, 14 and this enables correction for the degree of enlargement to be allowed for. The adjustments of variable resistors 5, 15 are coupled so that for increasing highlight density the flash exposure time is reduced. The apparatus is initially set up by exposing a sample of a film batch to a reflection density wedge, after setting the capacitor value to an optimum value, the highlight density control (resistors 5) to zero, shadow density control (resistors 15) to a minimum value. The resulting image is examined to discover the region corresponding to 5% and 95% dot, and any adjustment of capacitor 6 made to produce 95% dot in an area of zero highlight density. Further test exposures using the step wedge are then made to determine the quantity of flash exposure necessary to produce a 5% and 95% dot, and the difference in the value of the bands gives the basic density of the batch of film, and the shadow density control (resistors 15) is adjusted to this value by returning the control to its minimum position, loosened on its spindle and reset so that its scale in by the measured value. To make the half tone negative, the highlight and shadow density values are determined using a densitometer, the apparatus adjusted to these values, and the exposures made.
GB4548370A
1970-09-24
1970-09-24
Photographic explosure controller
Expired
GB1361392A
(en)
Priority Applications (3)
Application Number
Priority Date
Filing Date
Title
GB4548370A
GB1361392A
(en)
1970-09-24
1970-09-24
Photographic explosure controller
US00181472A
US3732011A
(en)
1970-09-24
1971-09-17
Apparatus for controlling the exposure of light sensitive material
DE19712147801
DE2147801A1
(en)
1970-09-24
1971-09-24
Watch control for reproduction cameras or the like
Applications Claiming Priority (1)
Application Number
Priority Date
Filing Date
Title
GB4548370A
GB1361392A
(en)
1970-09-24
1970-09-24
Photographic explosure controller
Publications (1)
Publication Number
Publication Date
GB1361392A
true
GB1361392A
(en)
1974-07-24
Family
ID=10437390
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
GB4548370A
Expired
GB1361392A
(en)
1970-09-24
1970-09-24
Photographic explosure controller
Country Status (3)
Country
Link
US
(1)
US3732011A
(en)
DE
(1)
DE2147801A1
(en)
GB
(1)
GB1361392A
(en)
Cited By (1)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US4297011A
(en)
1979-05-10
1981-10-27
Rollei Of America, Inc.
Photoflash device
Families Citing this family (8)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
SE363173B
(en)
*
1972-05-25
1974-01-07
Misomex Ab
US3882510A
(en)
*
1972-10-06
1975-05-06
Asahi Optical Co Ltd
Oscillation systems for control of camera shutters
JPS5050916A
(en)
*
1973-09-03
1975-05-07
US4175855A
(en)
*
1974-04-04
1979-11-27
Terminal Data Corporation
Electronic exposure control
US4302100A
(en)
*
1980-03-05
1981-11-24
Portage Newspaper Supply Company
Photographic direct-print system
US5351106A
(en)
*
1991-07-01
1994-09-27
Amergraph Corporation
Exposure system
US8907258B2
(en)
2010-04-08
2014-12-09
Ncc Nano, Llc
Apparatus for providing transient thermal profile processing on a moving substrate
ES2819216T3
(en)
*
2010-04-08
2021-04-15
Ncc Nano Llc
Apparatus for curing thin films on a moving substrate
Family Cites Families (5)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
CH418828A
(en)
*
1963-03-15
1966-08-15
Gretag Ag
Device for controlling the exposure in photographic copiers
CH458924A
(en)
*
1966-05-04
1968-06-30
Ciba Geigy
Device for controlling the exposure in photographic copiers for multicolor exposure
US3521952A
(en)
*
1967-07-13
1970-07-28
Robert H Nelson
Light exposure control unit
US3545858A
(en)
*
1968-03-11
1970-12-08
Warren Childers
Photographic timing apparatus responsive to optical density
US3611159A
(en)
*
1968-12-23
1971-10-05
Robertson Photo Mechanix Inc
Automatic-exposure-programming apparatus for a camera
1970
1970-09-24
GB
GB4548370A
patent/GB1361392A/en
not_active
Expired
1971
1971-09-17
US
US00181472A
patent/US3732011A/en
not_active
Expired – Lifetime
1971-09-24
DE
DE19712147801
patent/DE2147801A1/en
active
Pending
Cited By (1)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US4297011A
(en)
1979-05-10
1981-10-27
Rollei Of America, Inc.
Photoflash device
Also Published As
Publication number
Publication date
US3732011A
(en)
1973-05-08
DE2147801A1
(en)
1972-05-25
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Legal Events
Date
Code
Title
Description
1974-12-04
PS
Patent sealed [section 19, patents act 1949]
1976-04-14
PLNP
Patent lapsed through nonpayment of renewal fees
