Classifications

• • 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
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/28—Silver dye bleach processes; Materials therefor; Preparing or processing such materials
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F3/00—Colour separation; Correction of tonal value
  • G03F3/10—Checking the colour or tonal value of separation negatives or positives
  • G03F3/107—Checking the colour or tonal value of separation negatives or positives using silver halide photosensitive materials

Definitions

• the subject of the invention is a process for the manufacture of a screened photographic colour copy which simulates a multi-colour print, preferably a multi-colour offset print or letterpress print, in which the screened negative colour separations of the original which correspond to the individual colours, and optionally additionally the black separation, are individually and successively exposed onto a light-sensitive negative-positive-working photographic material, characterised in that at least one of the colour separations is additionally exposed onto the light-sensitive colourphotographic material using the copying light of a colour corresponding to a different colour separation, and that the material exposed in this way is processed to give a screened, positive direct-viewing image which shows prime colours which match the printing inks.
• the procedure followed is thus that the screened negative colour separations of the original (blue B, green G, red R, black S) are successively, in optional sequence and in register, individually exposed with the corresponding filters (blue b, green red r) onto a lighbsensitive negative-positive-working, colourphotographic material, B b, G g, R r and S with white light, the improved matching of the colour impression of the colour copy to the printing inks being achieved by additionally carrying out at least one of the following exposures: B g, B r, G b, G r, R b and R g.
• the exposures of the colour separations and of the admixture are computed from the densitometric measurement of the printing inks and of the photographic copy.
• the procedure followed is thus that, depending on the measured colour deviation of the individual prime colours of the fcolour proof from the printing ink or printed p rod net, a second and, if appropriate, a third screened colour separation negative is individually exposed, to a greater or lesser extent, with the light of the first colour separation negative, this being done in such a way that the proportion of the exposure of the additional second or third colour separation is as a rule 10 to 100 percent, preferably 20 to percent, of the exposure time of the first colour separation, that is to say the exposure times are in the ratio of 1:10 to 1:1, or 1:5 to 121.4.
• the matching of the individual prime colours of the colour proof to the printing conditions is achieved by lesser or greater exposure of the colour separations.
• the black separation can be exposed in two ways.
• simple method exposure is carried out with white light, without a filter.
• the black shade can vary, depending on the colour material used.
• sec- .ond method the shade can be influenced. This requires three exposures with the primary colours blue, green and red, and the black shade can be changed through the amount of light for each filter.
• the mostly black-and-white screened colour separation negatives correspond to the negatives usually employed in screened offset and letterpress printing technology. These screened negatives have as a rule been produced as direct screened separations by means of gravure or contact screens from colour direct-viewing originals and colour diapositives, either conventionally by means of a reproduction camera or an enlarger, or via so-called scanners.” The colour retouching and correction of the colour separations is matched to the works colour scale of the individual printing works.
• the screened negatives are individually copied onto a negative-positive-working photographic silver dye bleach material.
• the blue filter negative is copied with blue light, and then the green filter negative for the mixed exposure (30 percent of the blue filter negative exposure) is copied. Thereafter, the green filter negative is exposed with green light, the red filter negative is exposed with red light, the black print negative is exposed with white light. After these five exposures, the colourphotographic material is developed to give a positive direct-viewing image which comes close to the printed product manufactured with the same separations.
• the green filter negative is copied with green light (7.7 seconds behind a grey density of 0.3)
• the red filter negative is copied with red light (1.9 seconds behind a grey density of 0.3)
• the black print negative is additionally exposed with white light (3 seconds behind a grey density of 0.9).
• RELATIVE DENSITIES Relative densities Measuring filter Total exposure EXAMPLE 3 If purer printing inks are used, that is to say printing inks with lesser subsidiary colour densities, the colour proof must also be produced with purer colours. In this case, instead of using a chromogenic colourphotographic material, a material based on the'silver dye bleach process is used.
• Process for the manufacture of a screened photographic colour copy simulating a multi-colour print in which the screened negative colour separations of the original which correspond to the individual colours, and optionally additionally the black separation, are individually and successively exposed using their corresponding copying color light onto a light-sensitive negative-positive-working substractive photographic material, which comprises additionally exposing at least one of said screened negative colour separations onto the light-sensitive colour-photographic material using the copying light of at least one of the other color separations and processing the material exposed in this way to give a screened, positive direct-viewing image which shows prime colours which match the printing inks.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Printing Methods (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4372031

Family Applications (1)

Country Status (8)

Cited By (3)

Families Citing this family (4)

Citations (1)

• 1970
  • 1970-07-24 CH CH1129270A patent/CH544954A/de not_active IP Right Cessation
• 1971
  • 1971-07-16 US US00163496A patent/US3772015A/en not_active Expired - Lifetime
  • 1971-07-19 CA CA118,507A patent/CA959321A/en not_active Expired
  • 1971-07-19 DE DE19712136065 patent/DE2136065A1/de active Pending
  • 1971-07-21 GB GB3428571A patent/GB1317874A/en not_active Expired
  • 1971-07-22 FR FR7126914A patent/FR2103242A5/fr not_active Expired
  • 1971-07-23 NL NL7110210A patent/NL7110210A/xx unknown
  • 1971-07-23 BE BE770408A patent/BE770408A/fr unknown

Patent Citations (1)

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