GB994165A - Photographic colour printing - Google Patents

Photographic colour printing

Info

Publication number
GB994165A
GB994165A GB40486/62A GB4048662A GB994165A GB 994165 A GB994165 A GB 994165A GB 40486/62 A GB40486/62 A GB 40486/62A GB 4048662 A GB4048662 A GB 4048662A GB 994165 A GB994165 A GB 994165A
Authority
GB
United Kingdom
Prior art keywords
light
red
printing
filter
voltage
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
GB40486/62A
Inventor
Denis Manktelow Neale
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.)
Ilford Imaging UK Ltd
Original Assignee
Ilford 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 Ilford Ltd filed Critical Ilford Ltd
Priority to GB40486/62A priority Critical patent/GB994165A/en
Priority to US317190A priority patent/US3282190A/en
Priority to DE19631447505 priority patent/DE1447505A1/en
Priority to CH1308263A priority patent/CH438009A/en
Publication of GB994165A publication Critical patent/GB994165A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS 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
    • G03B27/00—Photographic printing apparatus
    • G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
    • G03B27/73—Controlling exposure by variation of spectral composition, e.g. multicolor printers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS 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
    • G03B27/00—Photographic printing apparatus
    • G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
    • G03B27/73—Controlling exposure by variation of spectral composition, e.g. multicolor printers
    • G03B27/735—Controlling exposure by variation of spectral composition, e.g. multicolor printers in dependence upon automatic analysis of the original

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectrometry And Color Measurement (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Projection-Type Copiers In General (AREA)

Abstract

994,165. Photo-electric control of photographic printers. ILFORD Ltd. Oct. 21, 1963 [Oct. 25, 1962], No. 40486/62. Heading G1A. [Also in Division G2] A method of photographic colour printing, which comprises allowing printing light to fall on a photo-cell, cyclically interposing in the path of said light a filter passing one spectral band but not another, adjusting the relative intensities of light in the two spectral bands until the alternating output of a logarithmic amplifier connected to the photocell attains a predetermined amplitude, and printing with light so adjusted. The red/green ratio of the printing light is measured by shining the light through a stationary yellow filter 2, Fig. 2, and rotating red filter sectors, 7, 8 on to a photomultiplier 1. The photomultiplier is connected in a known arrangement in which its anode current is maintained constant and the dynode voltage fed to the input of a logarithmic amplifier to produce an output voltage which is a logarithmic function of the incident light intensity. Provided the response to the cyclically interrupted light is at least ten times that to the steady light, the alternating component of the output voltage is proportional to the logarithm of the red/green ratio. The alternating voltage is amplified, rectified and fed to a cathode follower Fig. 4 (not shown). The voltage required from the cathode follower is set up on a further cathode follower using a test transparency and deviations from this value are indicated on a meter. The red/blue ratio may be similarly established by replacing the yellow filter by a magenta filter.
GB40486/62A 1962-10-25 1962-10-25 Photographic colour printing Expired GB994165A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
GB40486/62A GB994165A (en) 1962-10-25 1962-10-25 Photographic colour printing
US317190A US3282190A (en) 1962-10-25 1963-10-18 Photographic colour printing
DE19631447505 DE1447505A1 (en) 1962-10-25 1963-10-24 Process for making multicolor copies of transparencies on photographic material
CH1308263A CH438009A (en) 1962-10-25 1963-10-24 Method and device for the production of multicolor photographic prints

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB40486/62A GB994165A (en) 1962-10-25 1962-10-25 Photographic colour printing

Publications (1)

Publication Number Publication Date
GB994165A true GB994165A (en) 1965-06-02

Family

ID=10415144

Family Applications (1)

Application Number Title Priority Date Filing Date
GB40486/62A Expired GB994165A (en) 1962-10-25 1962-10-25 Photographic colour printing

Country Status (4)

Country Link
US (1) US3282190A (en)
CH (1) CH438009A (en)
DE (1) DE1447505A1 (en)
GB (1) GB994165A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3527540A (en) * 1967-05-08 1970-09-08 Itek Corp Color concentration discriminators
US3748035A (en) * 1971-12-28 1973-07-24 Xerox Corp Method for sequential illumination in a polychrome process

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2521954A (en) * 1946-05-10 1950-09-12 Eastman Kodak Co Apparatus for making color prints
US2544196A (en) * 1947-08-04 1951-03-06 Pavelle Color Inc Photoelectric color analyzer
US2565399A (en) * 1949-09-30 1951-08-21 Simmon Brothers Inc Machine for making photographic color prints
US3069971A (en) * 1960-01-18 1962-12-25 Simmon Brothers Inc Exposure control apparatus for making color prints
US2977407A (en) * 1960-02-10 1961-03-28 Hazeltine Research Inc Electronic previewer for photographic processes

Also Published As

Publication number Publication date
US3282190A (en) 1966-11-01
DE1447505A1 (en) 1968-10-24
CH438009A (en) 1967-06-15

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