Copying photographic originals with different density extent

摘要

The method uses a copying material for the matching of the contrast of the copying material to the requirements of the original, which has a distinct contrast dark plate effect. Namely, the gamma value alters considerably with the alteration of the exposure time. The illumination density of the original during the copying is so controlled that over the corresp. altered copying time (T), the contrast of the copying material is matched to the respective character of the original. The determination of the original character and the required copying material contrast, is executed automatically based on a sectional scanning of the original and a comparison of the measured density value distribution with distribution of known recording substance.