SU1538161A1 - Method of producing half-tone negative of black paint - Google Patents

Abstract

The invention relates to a method for producing a raster negative of black ink and allows eliminating an excess of black ink in bright halftones in the achromatic and photographically equivalent color portions of the reproduced image and preserving autotype elements throughout the negative. Direct shooting is carried out through a special mask and raster. The mask is made by contact exposure of a reproducible image with underexposure on a panchromatic halftone film. The exposure of the mask is carried out by a light source having a spectral composition of energy that is the same as when exposing a black ink negative. The latent mask image is developed to a gamma of one.

Description

The invention relates to photo reproduction processes, in particular, to the technology of making color-separated photoforms.

The aim of the invention is to improve the quality of negative black paint by eliminating excess black ki in bright halftones and preserving autotype elements throughout the image.

The essence of the invention is as follows.

The image obtained when using the mask in the process of direct shooting has an increase in density, which is opposite to the increase in density in bright halftones of achromatic and photographically equivalent color areas of the masked original,

and on the rest of the image there is no increase in density. When combining the image of such a mask with the masked original, as a result of overlapping of two opposite images in the areas of light tones of the achromatic and photographically equivalent color sections, the densities are aligned. Therefore, as a result of exposure through a raster on a raster negative of black paint, identical autotypic elements are formed in these areas, and in the rest of the image there is an increase in autotypic elements.

The range for eliminating excess black ink depends on the density range of the mask and can be easily adjusted by the duration of exposure.

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in the process of their manufacture. Consequently, it is possible to adjust the amount of black ink while retaining the autotype elements throughout the image}

The optimal level of eliminating excess black paint on a given range of achromatic tones is achieved by using a mask that develops to a gamma of one, i.e. when there is a masking image that is equal in contrast to the masked original. When using a mask of a smaller contrast than the masked original, a certain increase in autotype elements, i.e., is observed on the masked range of the image of the raster negative. Black ink raster negative will be unmasked If the mask image is more contrast than the masked original, the raster negative will be remasked. In order to obtain the required masking on the colored areas, it is necessary, along with the achievement of the required contrast, on the achromatic tones, to ensure the distribution of contrasts on the colored ones. To this end, the mask is exposed to a light source with a spectral distribution of energy similar to the light source a, used when removing raster black ink. If the spectral energy distributions of these sources do not match, one can observe a remasking of some colors and a lack of masking of others. Thus, if a raster negative of the black ink is made, for example, behind a yellow filter, then the mask should be exhibited behind the yellow filter.

In the process of making color separations using separate black and white masks for correcting negatives of yellow, magenta, and blue paints, a mask for correcting black ink is made by contact copying an unmasked original.

Example. The image of the original (color slide), masked by a single color mask, is copied onto a panchromatic crawl tone film p. The latent image of the exposed film is developed for 3.5 minutes in metolhydroquinone developer D-73 and fixed in

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5 min in acid fixer. After drying, the image of the resulting mask is combined with the image of the masked original and the exposure is carried out through a contact raster on a high-contrast FT-P2 film. The duration of exposure at a threefold increase is 90 pulses.

After chemical-photographic processing (3 minutes in the IP-6 developer and fixation for 5 minutes in acidic fixation), a raster negative of black ink is obtained, in which there is no excess paint in bright halftones in the achromatic and photographic color regions that are equivalent to them. elements throughout the image.

Example 2. The image of the original (color slide), masked by a single color mask, is exposed to a FT-12p panchromatic half-tone film by a yellow filter. The chemical-photographic processing of the exposed latent image is carried out in a manner similar to Example 1. The image of the finished mask is combined with the image of the masked original and the wire t exhibiting for a yellow light filter through a contact raster on a high-contrast film FT-112 p. Exposure time with a threefold increase in is put ON pulses.

After the chemical-photographic processing performed in the same way as in example 1, a raster negative of black ink is obtained, in which there is no excess of black ink in bright halftones in the achromatic and photographic color areas equivalent to them and minimal autotype elements are preserved throughout the image.

Example 3. The image of the original (color transparencies), masked by a single color mask, is exposed to FT-12 pachromatic film. The latent image of the exposed film is developed for 2 minutes in the metolhydroquinone developer D-73 and fixed for 5 minutes in acidic fixer After drying, the mask image is combined with the image of the masked original and the exposure is carried out through a contact raster on a high-contrast film FT5153.

112 p. Duration of exposure with a triple increase of 70 pulses. After the chemical-photographic processing performed in the same way as in example 1, a raster negative of black ink is obtained with an insufficiently reduced excess of paint in bright halftones in achromatic and photographically equivalent color sections and the presence of autotypic elements throughout the image. Get an unmasked negative.

Example 4. The image of the original (color transparencies), masked by a single color mask, is exposed to FT-12 pachromatic film. The latent image of the exposed film is developed for 5 minutes in the metolhydroquinone developer D-73 and fixed for 5 minutes in acidic fixer After drying, the mask image is combined with the image of the masked original and the exposure is carried out through a contact raster on an FT-112 high-contrast photographic film. The duration of exposure at a threefold magnification is 150 pulses. After chemical-photographic processing, performed according to the conditions, similar to example 1, get a raster

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negative, in which there are autotypic elements throughout the image, but the size of autotypic elements in the colors of the reproduced image is greater than in semitones. Therefore, the resulting negative is remasked.

Claims (1)

Invention Formula A method of making a raster negative of black ink consisting in direct shooting of a masked the original through a contact ratsr without a light filter or with light filters on a high contrast panchromatic film and its subsequent development, differing 0 by the fact that, in order to improve the quality of negative black ink by eliminating excess black ink in bright halftones and preserving autotype elements throughout the image, direct shooting is carried out through a mask, while the mask is obtained by contacting the masked original with underexposure on a panchromatic film followed by up to Q gamma is equal to one, and the spectral composition of the exposure radiation is equivalent to direct shooting radiation.