The use of partially transparent plates to increase the contrast of images.
Calculations and measurements were made for studying the effect of partially transparent plates in order to increase contrast. It was shown that, aside from their present use for images on photographic film, these plates may be used for increasing the contrast of paper images. The differences in contrast on low density areas of images on paper and film may be considerably increased without significantly influencing the contrast ratios of high density areas. The increase in contrast in all cases results in a loss of the illuminating light energy and in some degradation of resolution.
Bauer
G T
GT
Xerox Corporation, Rochester, NewYork 14603, USA.