Günter Wolfgang Wyszecki (November 08, 1925 – June 22, 1985) was a

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

Canadian Canadians () are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''C ...

physicist who made important contributions to the fields of

colorimetry Colorimetry is "the science and technology used to quantify and describe physically the human color perception". It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color p ...

and

color vision Color vision, a feature of visual perception, is an ability to perceive differences between light composed of different frequencies independently of light intensity. Color perception is a part of the larger visual system and is mediated by a co ...

Education and personal life

Wyszecki was born in Tilsit,

East Prussia East Prussia was a Provinces of Prussia, province of the Kingdom of Prussia from 1772 to 1829 and again from 1878 (with the Kingdom itself being part of the German Empire from 1871); following World War I it formed part of the Weimar Republic's ...

, Germany (today Sovetsk,

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

). He attended the

Technische Universität Berlin (TU Berlin; also known as Berlin Institute of Technology and Technical University of Berlin, although officially the name should not be translated) is a public university, public research university located in Berlin, Germany. It was the first ...

where he was awarded a Dr.-Ing. degree, with a dissertation on normal and anomalous trichromacy. In 1953 he was awarded a

Fulbright Scholarship The Fulbright Program, including the Fulbright–Hays Program, is one of several United States cultural exchange programs with the goal of improving intercultural relations, cultural diplomacy, and intercultural competence between the people ...

and for a year joined Deane B. Judd at the

Colorimetry Colorimetry is "the science and technology used to quantify and describe physically the human color perception". It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color p ...

and

Photometry Photometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electr ...

section of the U. S.

National Bureau of Standards The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sc ...

in Washington DC. He was married to Ingeborg Wyszecki, and had two children named Joana & Wolfgang. He became a naturalized Canadian citizen in 1961.

Career

In 1955 Wyszecki joined the

National Research Council of Canada The National Research Council Canada (NRC; ) is the primary national agency of the Government of Canada dedicated to science and technology research and development. It is the largest federal research and development organization in Canada. Th ...

Ottawa Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...

where he became the leader of its Optics Section in 1960 and Assistant Director of the Division of Physics in 1982, and where he remained until his untimely death from leukemia. Wyszecki is best known for his scientific contributions to and leadership in the

International Commission on Illumination The International Commission on Illumination (usually abbreviated CIE for its French name Commission internationale de l'éclairage) is the international authority on light, illumination, colour, and colour spaces. It was established in 1913 a ...

(CIE). He was chairman of its Colorimetry Committee from 1963 to 1975, vice president of the organization from 1979 to 1983 and its president from 1983 until his death. During this period the CIE made many important recommendations in colorimetry, remaining valid today, such as 1 nm tables of the color-matching functions of the two CIE standard observers and the standard illuminants A and D65, addition of integrating-sphere reflectance factor measurement as a recommended measuring geometry, the 1964 (U*V*W*) and the 1976 CIELAB and CIELUV uniform color space and color difference formulas, and others. ''Metamerism:'' Wyszecki introduced the important concept of ‘metameric blacks,’ psychophysical definitions of blacks with tristimulus values 0, 0, 0 that within limits can be added to a spectral reflectance to form the various possible metamers (with an identical set of tristimulus values) under a given light. With Walter Stiles he also developed mathematical methods to calculate by various methodologies the number of possible metamers for given chromaticities, peaking at the achromatic colors. ''Wyszecki seven-field colorimeter:'' In 1965 Wyszecki developed the seven-field colorimeter with which an observer can view with both eyes one or more of seven hexagonal fields, each with separately controllable RGB sources achieved with filtered light, mixed in an integrating sphere. ''Color matching and color-difference matching:'' David MacAdam's color-matching error ellipses of 1942 (1 observer) were extended in 1957 for 12 observers by Brown and in 1971 by Wyszecki and Fielder. The latter two investigations demonstrated the considerable variability by observer. The seven-field colorimeter was also used for a novel color-difference matching experiment in which three fields were displayed and the observer had to adjust the third field so that its brightness matched the brightness of preselected colors with equal luminance in two fields and its chromaticity resulted in identical perceived differences between the colors in the triangular arrangement. ''Heterochromatic brightness matching:'' Wyszecki and co-workers also added important experimental data to the luminance of equally bright stimuli. Many chromatic stimuli, when compared to achromatic ones of the same psychophysical brightness or lightness appear to be lighter or brighter, to be "glowing," an effect known as the

Helmholtz–Kohlrausch effect The Helmholtz–Kohlrausch effect (named after Hermann von Helmholtz and V. A. Kohlrausch) is a perceptual phenomenon wherein the intense saturation of spectral hue is perceived as part of the color's luminance. This brightness increase by sat ...

Publications

Wyszecki authored or co-authored 86 scientific papers and 3 books. The first book, ''Farbsysteme'' was published in Germany in 1960, describing color order systems. He co-authored together with Deane Judd the second and third editions of the latter's Color in Business, Science and Industry, the third edition after the passing of Judd. He was the lead author, together with Stiles, of the monumental ''Color Science: Concepts and Methods, Quantitative Data and Formulae'', with editions in 1967 and 1982. The second edition remains in print today as a highly important source of information in the field of color science.

References

{{DEFAULTSORT:Wyszecki, Gunter 1925 births 1985 deaths People from Tilsit People from East Prussia German emigrants to Canada 20th-century Canadian physicists 20th-century German physicists Color scientists