GB795064A - Process for improving colour reproduction by means of subsequent masking when reproducing photographic subtractive multi-colour images - Google Patents

Abstract

795,064. Photographic colour correction AGFA AKT.-GES., [formerly AGFA AKT. GES. FUR PHOTOFABRIKATION]. June 14, 1955 [June 14, 1954], No. 17141/55 Addition to 755,458. Class 98(2) The process of the parent Specification in which colour corrected prints are made from a multicolour image by printing the latter through one or more masks described as "coloured correctives" and constituting an optical combination of a colour separation record with another colour separation record of opposite but otherwise similar gradation, both records being formed of dyes of the same colour, this colour having the same absorption as the unwanted absorption of the partial dye images to be corrected, is modified by the feature of at least two of the correctives being produced in a single photographic layer or in separ ate layers arranged on a common support. This feature is illustrated in Fig. 2, thus if the a and b of Fig. 1 which represent separate sensitive materials are assembled as in Fig. 2 using a common support T, exposed in contact with the multicolour image using light of colour for which reference is made to the parent Specification and processed to the gradation and colours of Fig. 1a the result would be one of the " coloured correctives" of the invention. Layers 1, 3 of Figs. 1, 2 are stated to be silver halide reversal layers; 2, 4 are normal layers and appropriate colour formers are included therein, G is a yellow filter. In Fig. 3 the layers 2, 3 of Figs. 1, 2 are, in a way, combined; layer 2 and 3 being stated to be a silver halide reversal layer containing a yellow-coloured coupler which is to be converted into magenta dye at places where a silver image is formed. Fig. 4 has two masking image layers only, both containing coloured colour couplers, and Fig. 5 adds the red sensitive layer of Fig. 3 to this. Figs. 6, 7 indicate the use of other coloured colour couplers. Colour production by dye-bleach, toning, and imbibition transfer procedure is mentioned in the Specification as well as by colour coupling. Specifications 599,377 and 665,657 are referred to.