Colour reproduction by photography

Abstract

The subjective and objective terms necessary for discussing colour are explained, and the various possible aims for colour reproduction in pictures are discussed, The tone reproductions required for reflection prints and for displayed transparencies are described and their differences explained. The methods used for forming the cyan, magenta and yellow dye images in colour photography are described; the unwanted retinal stimulations produced by the bands of the spectrum modulated by the dyes are shown to restrict the reproducible colour gamut and to call for unattainable negative lobes in the spectral sensitivity curves of the film layers; the unwanted absorptions of the dyes are also shown to reduce the reproducible colour gamut. The ways in which the effects of these unwanted stimulations and unwanted absorptions are mitigated so that excellent colour quality can be attained are described. Factors affecting the granularity and sharpness of colour photographs are discussed, and the methods adopted for the mass-printing of amateurs' negatives are described. Finally, brief descriptions are given of systems of colour photography in which the picture is processed in the camera.