GB1350270A - Process for the production of negative continuous-tone images - Google Patents

Abstract

1350270 Negative continuous tone image production using silver halide material AGFA GEVAERT AG 19 April 1971 [18 April 1970] 27270/71 Headings G2C and G2X Negative continuous-tone images or continuous tone colour separation records are produced in a camera or by contact with originals by exposing a photographic material having at least one light-sensitive silver halide emulsion layer, which may be a mixed emulsion layer, to black white or multi-coloured originals of different density ranges, wherein the characteristic curve of the light-sensitive silver halide emulsion layer has a continuously increasing positive gradient in a log I x t interval h ranging at least over the greatest density range of all the originals, and the lower the density range of the originals, the steeper is the part of the characteristic curve in which they are reproduced. The density at the half-way point of the interval h of the characteristic curve of the silver halide emulsion layer may be higher than the value at the start of the characteristic curve by 106-40 per cent of the density range U K and the curve may have a maximum sag of at most 50 per cent U K situated in the third or fourth fifth of the interval h. Continuous tone positives may be made from the above produced negatives by exposing a photographic silver halide material having a gradation which can be altered by the colour of the light used, to the negatives. Screened positive images may also be produced from these negatives using a coloured contact screen and a photographic silver halide material having a gradation of more than 7, the optical density of which material can be varied by the colour of the copying light.