Eltra Corporation

William J Pickering

Peter J Neilson

Four color separations are produced from a single full-color photographic transparency. The transparency is mounted on the transparent curved surface of a rotatable cylinder and light is directed axially into the cylinder and out through the transparency to a photomultiplier. The illumination of the transparency is provided by red, blue and green light in time sequence, and the itensity from each color is stored separately while the transparency is being scanned and used to produce the separations contemporaneously on photosensitive paper on a second cylinder. The transparency is scanned axially of the first cylinder, which is rotated. The relative speed of rotation of the cylinders is used as a control of the magnification of the reproduced separations. A further photomultiplier is used to provide unsharp masking, and color correction is applied between the color intensities detected by the photomultiplier.

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Winchcombe, United Kingdom

William J Pickering