By using the relationship between the spectral densities of specimens of a given kind of color film at three separated wavelengths and their chromaticities, integral color densitometer data can be correlated with dominant wavelength and purity data. Transformation grids are prepared to facilitate this conversion.
Color film balance can be represented by a series of vectors, each drawn from different density levels along a density vs log exposure curve. The vectors represent, by their directions, the dominant wavelengths of the corresponding gray-exposed patches of the sensitometric strip and by their lengths, the extent of the departure from gray balance. For any particular case, a grid can be prepared which relates the vectors to the corresponding Munsell colors of the patches. In a similar way, the correlation between the vectors and the filtration of the light source necessary to correctly reproduce gray can be established and utilized in grid form.
Although developed primarily for three-layer reversible color film, the treatment is applicable to any three-color reproduction process.
© 1952 Optical Society of AmericaFull Article | PDF Article
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