US2220882A - Film treatment - Google Patents

Film treatment Download PDF

Info

Publication number
US2220882A
US2220882A US271945A US27194539A US2220882A US 2220882 A US2220882 A US 2220882A US 271945 A US271945 A US 271945A US 27194539 A US27194539 A US 27194539A US 2220882 A US2220882 A US 2220882A
Authority
US
United States
Prior art keywords
film
infra
red
flashing
exposure
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 - Lifetime
Application number
US271945A
Other languages
English (en)
Inventor
Charles D Bennes
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.)
Technicolor Motion Picture Corp
Original Assignee
Technicolor Motion Picture Corp
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
Priority to BE438293D priority Critical patent/BE438293A/xx
Application filed by Technicolor Motion Picture Corp filed Critical Technicolor Motion Picture Corp
Priority to US271945A priority patent/US2220882A/en
Priority to GB2749/40A priority patent/GB537928A/en
Priority to FR863696D priority patent/FR863696A/fr
Application granted granted Critical
Publication of US2220882A publication Critical patent/US2220882A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • G03B15/00—Special procedures for taking photographs; Apparatus therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
    • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
    • G03C5/32—Latensification; Densensitisation

Definitions

  • the present invention comprises a method of increasing the effective speed far beyond the inherent speed of 10 the emulsion, however fast the emulsion may be as aresult of original compoundingor subsequent hypersensitizatlon.
  • Objects of the invention are to providesuch a method which is applicable after the film has 15 been exposed to form latent images therein;
  • emulsions may be sensitized, which can be applied quickly and cheaply, in which the tendency 2 to produce oblectional fog is slight and readily controlled, which can be readily and accurately controlled to regulate the degree of increase of efiective speed, which can therefore be used to control the color balance between the difi'erent 25 color component records of pictures in natural.
  • treating the film of photographic emulsion comprises exposing the film to form a latent image and subsequently developing the latent image, characterized in that the latent image, before 7 being developed, is intensified by flashing the 40 film with infra-red radiation.
  • the infra-red radiation acts upon the silver halide of the latent image to render it-more readily reducible, so that a. developed image of predetermined density can be obtained with a lesser ex- 45 posure than is possible without the infra-red flashing.
  • Fig. 1 is a front elevation of a flashing machine
  • Fig. 2 is a section on line 22 of Fig. 1.
  • a The particular ma chine chosen for the purpose 5 of illustration comprises a frame I, a lamp house 2, a feed-reel I, a take up reel 4 and a drum 5 over which film is fed from the feed-reel to the take-up reel.
  • an opening 6 is provided in line with the periphery of the drum 5 so that rays from the lamp 5 I may radiate to the film passing over the drum 5.
  • a filter 8 which transmits infra-red rays but absorbs substantially all of the visible light.
  • the filter 8- is preferably a Corning No. 254 infra-red filter.
  • the machine By making the housing 2 light-tight the machine may be operated in a dark room without enclosing the film.
  • a fan 9 draws air into the housing through light-bailied openings 10 at the sides of the housing and forces it out through a light-bellied opening I I.
  • the drum 5 is driven at constant speed through shaft l2 leading to a source of power (not shown), the periphery of the drum preferably being covered with rubber to prevent slipping of. the film.
  • the feed-reel 3 is prevented from overrunning by the usual brake (not shown) and take-up reel 4 is driven by shaft l3 somewhat faster than the drum 5 through the usual friction clutch so as to take up the film as rapidly as it is delivered by the drum 5.
  • a 1000 watt Mazda lamp .of the concentrated filament type about 8" from the film a light opening about 3 long, and a Corning No. 254 filter approximately 1 mm. thick, high-speed negative film may be run as fast as 130' per minute with excellent results, which results in an exposure of somewhat more than 6 second.
  • the aforesaid Corning filter No. 2'54 which is the best filter readily available, transmits a slight 5 amount of red light which would produce objectionable fog if the exposure is too long.
  • the maximum flashing exposure may readily be determined by gradually increasing the exposure until the fogging effect becomes objectionable.
  • the proportion of red transmission may be reduced because the transmission for red light falls off faster with increasing thickness than that for infra-red radiation.
  • the magnitude of the flashing exposure maybe further increased, still further to increase the efiective speed of the film.
  • the slight decrease in contrast of the developed plcture may ii desired be' counteracted by a slight so increase in development time. ,1
  • the efi'ect of infra-red radiation is relatively independent of the color sensitivity of the film, so that approximately the same eifect may be obtained with the same treatment in treating film having difi'erent color sensitivity.
  • This is particularly important in treating sets of color-separation film of different color sensitivity, such as three negatives predominantly sensitive to red, green and blue respectively.
  • the color-selective emulsions are all carried by the same support, either in superposed layers or intermingled, this advantage is even more important, particularly where all emulsions are to be afiected in approximately the same degree.
  • infra-red treatment herein described is not to be confused with so-called incubation; that is a small elevation of temperature for long periods of time.
  • the treatment herein described and claimed is not only much more effectiye than incubation but can be applied in a fraction of a second instead of requiring hours or even days.
  • Incubation is also inferior in that it shrinks the film, which is particularly serious in color-cinematographic processes where shrinkage interferes with the registration of the diiIerent color components of the pictures.
  • the method which comprises forming a latent image in the film by exposure to visible light, flashing the film with infra-red radiation, and developing the latent image.
  • the method which comprises forming a latent image in the film by exposure to visible light, rendering the exposed silver-halide particles more easily reducible by flashing the latent image with infra-red radiation, and then reducing the exposed silver halide to form a picture.
  • the method which comprises forming latent images. in the film by exposure to visible light, continuously feeding the film past a source of infra-red radiation to intensify the latent images by flashing with infra-red radiation, and developing the latent image.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
  • Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
  • Stroboscope Apparatuses (AREA)
US271945A 1939-05-05 1939-05-05 Film treatment Expired - Lifetime US2220882A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE438293D BE438293A (is") 1939-05-05
US271945A US2220882A (en) 1939-05-05 1939-05-05 Film treatment
GB2749/40A GB537928A (en) 1939-05-05 1940-02-13 Improvements in the treatment of photographic films
FR863696D FR863696A (fr) 1939-05-05 1940-03-05 Mode de traitement de films cinématographiques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US271945A US2220882A (en) 1939-05-05 1939-05-05 Film treatment

Publications (1)

Publication Number Publication Date
US2220882A true US2220882A (en) 1940-11-12

Family

ID=23037756

Family Applications (1)

Application Number Title Priority Date Filing Date
US271945A Expired - Lifetime US2220882A (en) 1939-05-05 1939-05-05 Film treatment

Country Status (4)

Country Link
US (1) US2220882A (is")
BE (1) BE438293A (is")
FR (1) FR863696A (is")
GB (1) GB537928A (is")

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2647068A (en) * 1948-03-16 1953-07-28 Bishop H Russell Process of treating vitreous materials
US3152902A (en) * 1959-09-14 1964-10-13 Cons Electrodynamics Corp Rapid latensification of printout material
US3661583A (en) * 1970-11-09 1972-05-09 Eastman Kodak Co Thermal desensitization of photosensitive systems

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2647068A (en) * 1948-03-16 1953-07-28 Bishop H Russell Process of treating vitreous materials
US3152902A (en) * 1959-09-14 1964-10-13 Cons Electrodynamics Corp Rapid latensification of printout material
US3661583A (en) * 1970-11-09 1972-05-09 Eastman Kodak Co Thermal desensitization of photosensitive systems

Also Published As

Publication number Publication date
FR863696A (fr) 1941-04-07
GB537928A (en) 1941-07-14
BE438293A (is")

Similar Documents

Publication Publication Date Title
ES446881A1 (es) Un metodo de formar una imagen fotografica en color.
US3442648A (en) Photographic dodging method
US2220882A (en) Film treatment
US1966322A (en) Method and apparatus for photographic printing
US3160504A (en) Automatic dodging of photographs
US2203652A (en) Color correction
US3143414A (en) Process for preparing direct positives
US3282183A (en) Photographic apparatus for recording, processing, and projecting data for rapid visual inspection
US2543706A (en) Method of counteracting average density fluctuation in motion pictures
US1900877A (en) Nonhalation motion picture film
US2168971A (en) Method of increasing the effective speed of a photographic element
US2609294A (en) Cinematographic matte
EP0104351B1 (en) Gelatin silver halide photographic elements for tanning development
US2244304A (en) Photographic process
US4256825A (en) Photographic element and photographic record prepared therefrom
US2179790A (en) Photographic developer
US3130053A (en) Photographic material for the production of photographic records with tone value correction
US2201591A (en) Photographic processing
US3241960A (en) Method for making vectographs
US2362593A (en) Method of masking color transparencies
US3851968A (en) Method for photographing a set of varying contrast radiographic x-rays
US2384612A (en) Combination field-evening and color-correction photographic mask
US2199580A (en) Photographic printing
GB529041A (en) Improved photographic process and light-sensitive elements therefor
US2403428A (en) Intensification of the latent image