Color Reproduction and Colorimetry
Subject is not scheduled Not scheduled
Name of lecturer(s)
Learning outcomes of the course unit
The development of color photography, color television and color printing demands a very wide and deep understanding of the facts of color mixture and color perception. These methods of color reproduction all have many interesting technical problems to solve, while physiologically, the processes in the eye and the brain exercise their own subtle influences on the visual apperance of a color reproduction. Moreover, the final assessment of a color picture calls for aesthetic as well as scientific appraisal.
The historical survay of existing methods of color reproduction continues with introduction to colorimetry, visual perception and their confrontation with practical means employed in color reproduction.
Mode of study
Classes are supplemented with extensive samples and image material
Prerequisites and co-requisites
basics of math and Physics
Course outline in basic chapters
1/ Physical and Trichromatic Color Reproduction – the micro-dispersion method, the Lippmann method, the Maxwell method, the mosaic methods, the lenticular methods, the subtractive principle, relief-images.
2/ The Color Triangle – color terminology, trichromatic matching, Grassmann´s laws, tristimulus color space, negative tristimulus values, color matching functions, NPL trichromator, transformation of primaries, CIE 1931 chromaticity diagram, properties of the XYZ system, uniform chromaticity diagram, uniform color scales, spectrophotometry, colorimeters.
3/ Visual Appreciation – the basis of judgement, variations in hue, lightness and saturation, priorities, factors affecting apparent color balance, the physiology of human color vision, spectral sensitivity curves of the retina, defects of trichromatic color reproduction, errors in additive methods, defects of subtractive principle, the Ives-Abney-Yule compromise.
4/ Adaptation and Exact Color Reproduction – change in appearance of colors as the adapting conditions change, dark and bright surroundings, influence on the contrast of the image, constancy of perception, conditions of exact color reproduction, memory colors, preferred color reproduction, comparative and single stimulus methods.
5/ Subtractive Methods in Color Photography – primary and secondary color development, integral tripacks, processing with the couplers incorporated in the film, reversal processing, processing with the couplers in developers, the philosophy of color negatives.
6/ Masking and Colored Couplers – conrast masking, colored couplers, inter-image effects, inter-image effects, masking when making separations, masking for exact color reproduction, masking for approximate color reproduction, calculation of mask contrasts.
7/ Chemistry of Color Photography – color development, developing agents, couplers, colored couplers, the dye-coupling reaction, the physical form of the dye, color developing solutions, silver bleaching, processing sequences.
8/ Printing – printing motion picture negatives, integrating to gray, printing amateurs´negatives, the variables to be corrected, early printers, color analyzers, additive and subtractive printers, digital scanning, laser recording.
9/ Recent Photographic Materials – design and structure of negative, reversal and positive photographic materials, materials with transparent and non-transparent base, intermediate materials, digital intermediate, instant photographic materials, zero-order diffraction process for color reproduction.
Recommended or required reading
Joseph S. Friedman: History of Color Photography, The American Photographic Publishing Comp., 1947
Michale J.Langford: Advanced Photography, The Focal Press, 1972
Grant Haist: Modern Photographic Processing, John Wiley and Sons, 1979
L.F.A. Mason: Photographic Processing Chemistry, The Focal Press, 1966
R.W.G. Hunt: The Reproduction of Colour, Fountain Press, London, 1967
Dean B.Judd, Gunter Wyszecki : Color in Business, Science and Industry, John Wiley and Sons, 1975
Assessment methods and criteria
This course has not lost sight of the practical side; lectures are complemented by experiments, tests and practical demonstrations. The subjects are treated more from the standpoint of technique rather than science in the hope of rendering the program more useful for practical applications.
No schedule has been prepared for this course