GB581408A - Improvements in photometric exposure meters for photographic apparatus - Google Patents

Improvements in photometric exposure meters for photographic apparatus

Info

Publication number
GB581408A
GB581408A GB1950343A GB1950343A GB581408A GB 581408 A GB581408 A GB 581408A GB 1950343 A GB1950343 A GB 1950343A GB 1950343 A GB1950343 A GB 1950343A GB 581408 A GB581408 A GB 581408A
Authority
GB
United Kingdom
Prior art keywords
comparison
negative
aperture
projected
piece
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
GB1950343A
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.)
ARCHER PEARSON
Original Assignee
ARCHER PEARSON
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 ARCHER PEARSON filed Critical ARCHER PEARSON
Priority to GB1950343A priority Critical patent/GB581408A/en
Publication of GB581408A publication Critical patent/GB581408A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
    • G01J1/12—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using wholly visual means
    • G01J1/122—Visual exposure meters for determining the exposure time in photographical recording or reproducing
    • G01J1/124—Visual exposure meters for determining the exposure time in photographical recording or reproducing based on the comparison of the intensity of measured light with a comparison source or comparison illuminated surface

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Eye Examination Apparatus (AREA)

Abstract

581,408. Comparison photometers and exposure meters. PEARSON, A. Nov. 22, 1943, No. 19503. [Classes 97 (i) and 98 (i)] A comparison photometer or projection printing exposure meter comprises a ground a of semi-opaque paper on to which the light transmitted by the negative is projected, and having beneath it a white card in which is cut a small aperture k through which the comparison light is projected. A tube b extends below the aperture k and contains diffusing material, such as a piece'of parchment paper, and a piece of film having the transparency of the high lights of the negative. A lamp c is the comparison light and may be tinted blue or covered with blue-tinted material. Its intensity is controlled by two resistances e, f, the latter being adjusted, by means of a knob g - geared to scales h, i, giving readings of different sensitivities. A third scale j may be provided. The resistance e is varied to suit any particular circumstances such as voltage fluctuation or the particular desired intensity. The resistance f provides the desired adjustment of luminosity at the aperture b for matching purposes, and is graduated from measurements and adjustments made with a negative of a normal subject. Specification 380,430, is referred to.
GB1950343A 1943-11-22 1943-11-22 Improvements in photometric exposure meters for photographic apparatus Expired GB581408A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1950343A GB581408A (en) 1943-11-22 1943-11-22 Improvements in photometric exposure meters for photographic apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1950343A GB581408A (en) 1943-11-22 1943-11-22 Improvements in photometric exposure meters for photographic apparatus

Publications (1)

Publication Number Publication Date
GB581408A true GB581408A (en) 1946-10-11

Family

ID=10130435

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1950343A Expired GB581408A (en) 1943-11-22 1943-11-22 Improvements in photometric exposure meters for photographic apparatus

Country Status (1)

Country Link
GB (1) GB581408A (en)

Similar Documents

Publication Publication Date Title
US3402636A (en) Method and means for automatically adjusting the light projection in microfilm cameras
GB1439096A (en) Device for document filming
US2172634A (en) Photographic exposure meter
GB605945A (en) Photographic and kinematograph camera with diaphragm opening indicator
US3227040A (en) Color head
GB581408A (en) Improvements in photometric exposure meters for photographic apparatus
US2147902A (en) Apparatus for determining photographic exposures
US2579661A (en) Light measuring meter
US2043589A (en) Photoelectric colorimeter
GB938927A (en) Improvements in or relating to photographic exposure meters
Goodwin The photronic photographic exposure meter
US2608125A (en) Color density analyzer
US2092588A (en) Light gauge for photometers
GB490464A (en) Improvements in or relating exposure meters for photographic enlargements
GB1477718A (en) Apparatus for providing a measure of the intensity of light
Grindley Apparatus for a Group Demonstration of Weber's Law.
GB439224A (en) Improvements in or relating to photo-electric exposure meters and attachments therefor
SU128659A1 (en) A device for determining fat in milk by transparency
GB590582A (en) Improvements in or relating to exposure meters for use with photographic enlargers
US2354545A (en) Optical exposure meter
US1414972A (en) Computing exposure meter
GB475465A (en) Photographic camera with photo-electric exposure meter
GB654250A (en) Improvements in or relating to devices for measuring the light cast by a photographic enlarger toward a surface
US1514665A (en) Method of ascertaining the actinic value of light for photographic purposes
GB361103A (en) Photo printing device