摘要 |
A method of and apparatus for measuring the optical density of an original, especially a three-color negative, from which photographic prints are made, to control how much printing light of each color penetrates the original when the image is projected onto a color print medium that is sensitive to these colors. The spectral sensitivity of the measuring apparatus is adjusted to that of the print medium. Measuring light is projected through the original and is resolved into at least one spectrum. The intensities of the light at the various ranges of wavelength are weighted and totaled in accordance with the spectral sensitivity of the particular print medium. Light valves with translucencies that can be adjusted to the sensitivity of the print medium to that range of wavelengths are distributed along the spectrum. The accordingly weighted intensities of the light of each color are separately sensed and measured.
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