GB867518A - Four-colour photographic reflected vision colour prints - Google Patents

Abstract

867,518. Copying by scanning. GRETENER A.G., EDGAR. May 14, 1958 [May 15, 1957], No. 15561/58. Class 40(3) [Also in Group XX] A coloured photographic reflected vision print comprises a neutral grey and three colour recordings on a white reflecting background. The print is produced by analysing an original colour transparency by means of a flying-spot scanner and associated photo-electric devices (Fig. 4, not shown) to produce sets of electrical signals representative respectively, of the neutral grey density and of the three (red, green and blue) "colour residue" densities these signals then being recorded as photographic images on separate transparencies from which the final print is produced, the neutral grey image being recorded as a conventional variable density transparency whilst the colour residue images are recorded by a variable area technique as described in Specifications 704,415 and 733,446. Fig. 1 shows the final form of the print which comprises a white reflecting backing 10 on which are superimposed the cyan, magenta and yellow images records 11, 12 and 13 respectively and the neutral grey image record 14. If desired, however, a single mixed grain emulsion layer may be employed for some or all of the images. In the print of Fig. 1, the resultant reflected colour is determined by the ratio of the coloured and pellucid elements such as 20 and 21 respectively, which result from variable area recording in not more than two superimposed layers since with the colour residue technique one of the colours is always zero the brightness of such colour being determined by the neutral grey layer. Types of film which are suitable for producing the final print by conventional photographic techniques are described with reference to Figs. 3 and 5 (not shown). Specification 867,517 also is referred to.