GB629658A - Improvements in or relating to exposure - Google Patents

Improvements in or relating to exposure

Info

Publication number
GB629658A
GB629658A GB28719/46A GB2871946A GB629658A GB 629658 A GB629658 A GB 629658A GB 28719/46 A GB28719/46 A GB 28719/46A GB 2871946 A GB2871946 A GB 2871946A GB 629658 A GB629658 A GB 629658A
Authority
GB
United Kingdom
Prior art keywords
flap
light
exposure
auxiliary source
screen
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
GB28719/46A
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.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of GB629658A publication Critical patent/GB629658A/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
    • G01J1/20—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle
    • G01J1/22—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means

Abstract

629,658. Photometers. FUCHS, F., and WEIDMANN, H. Sept. 25, 1946, No. 28719. Convention date, Dec. 5, 1941.. [Classes 97 (i) and 98 (i)] An exposure meter of the equal brightness of field type comprises a mirror 1 which reflects an image projected by an enlarger, on to a translucent screen 4 viewed by transmitted light, and means, as a flap 10 controlled by a cord 12 attached to a winch 11, for regulating the amount of light coming from an auxiliary source 7 which illuminates a reflecting opaque comparison surface 5 provided on the screen 4, the position of the adjusting means providing a factor for use in calculating the printing exposure. The two illuminated fields may be observed through a magnifying glass 6. Instead of a flap 10, the light from the auxiliary source passing to the surface 5 may be adjusted by a grey wedge, the resistance in the lamp circuit, or by crossed polarizers.
GB28719/46A 1941-12-05 1946-09-25 Improvements in or relating to exposure Expired GB629658A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH629658X 1941-12-05

Publications (1)

Publication Number Publication Date
GB629658A true GB629658A (en) 1949-09-26

Family

ID=4524657

Family Applications (1)

Application Number Title Priority Date Filing Date
GB28719/46A Expired GB629658A (en) 1941-12-05 1946-09-25 Improvements in or relating to exposure

Country Status (1)

Country Link
GB (1) GB629658A (en)

Similar Documents

Publication Publication Date Title
US3754824A (en) Light color control apparatus
US2431612A (en) Picture and map projector
GB629658A (en) Improvements in or relating to exposure
GB1268276A (en) Improvements in episcopes
GB1144815A (en) A method of, and apparatus for, reversing and/or controlling the contrast of an image
GB472013A (en) Improvements in and relating to apparatus for taking and/or projecting continuously moving kinematographic films
GB1144813A (en) Photographic exposure value compensator
DE919859C (en) Photographic lens with illuminated aperture ring
GB439224A (en) Improvements in or relating to photo-electric exposure meters and attachments therefor
DE700426C (en) Hand-held device for measuring the brightness of image-important parts of the projected image during photographic enlargement
DE737158C (en) Device for the projection of images with optical compensation
GB401511A (en) Improvements in methods and apparatus for the photographic reproduction of letterpress printing formes
GB417740A (en) Device for measuring the density of photographic negatives and copying the same
GB536465A (en) Light control by polarisation
GB378429A (en) Exposure meter
GB634572A (en) Cinematograph continuous film-feed projector
GB664544A (en) An optical projector device for precise laboratory balances
GB544564A (en) Improvements in and relating to x-ray apparatus
GB590582A (en) Improvements in or relating to exposure meters for use with photographic enlargers
GB603253A (en) Improvements in or relating to photographic projection printing apparatus
GB1191116A (en) Photographic Viewfinder
GB1036062A (en) Optical projector
GB746761A (en) Illuminating apparatus for coloured film printer
GB380430A (en) Apparatus for estimating the exposure time in photographic printing
GB477115A (en) Optical apparatus for composing and/or decomposing colours