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David Lewis MacAdam (July 1, 1910 – March 9, 1998) was an American
physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...
and color
scientist A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosop ...
who made important contributions to color science and technology in 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 ...
, color discrimination,
color photography Color photography is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white or gray- monochrome photography records only a single channel of luminance (brightness) and uses media capable only of ...
and
television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising, ...
, and color order.


Education

MacAdam grew up in Upper Darby outside of
Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Since ...
, graduating from
Upper Darby High School Upper Darby High School (UDHS) is a four-year public high school located in Upper Darby Township, Delaware County, Pennsylvania, United States, as part of the Upper Darby School District. UDHS is also the oldest high school in Delaware County, ...
in 1928, attended
Lehigh University Lehigh University (LU) is a private research university in Bethlehem, Pennsylvania in the Lehigh Valley region of eastern Pennsylvania. The university was established in 1865 by businessman Asa Packer and was originally affiliated with the Epi ...
, and in 1936 received a PhD in physics from MIT. Under Prof. Arthur C. Hardy, he originated the first course in color measurement and assisted Hardy in the preparation of “Handbook of Colorimetry,” published in 1936.


Career

Upon graduation MacAdam joined the Research Laboratories of the Eastman Kodak company in Rochester, NY, from where he retired as a Senior Research Associate in 1975. Subsequently, he was named Adjunct Professor at the
University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of ...
, Institute of Optics where he remained active until 1995. At Eastman Kodak, among many other things, he helped to establish the theoretical basis for
color photography Color photography is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white or gray- monochrome photography records only a single channel of luminance (brightness) and uses media capable only of ...
, including color masking as compensation for unwanted dye layer absorptions.


Optimal object color limits

While still studying, MacAdam published in 1935 two papers on the theory of optimal object colors in which he showed the results of his calculations of the optimal object color solid raised over the
CIE chromaticity diagram The CIE 1931 color spaces are the first defined quantitative links between distributions of wavelengths in the electromagnetic visible spectrum, and physiologically perceived colors in human color vision. The mathematical relationships that defi ...
, using the newly established CIE standard observer and
illuminant A standard illuminant is a theoretical source of visible light with a spectral power distribution that is published. Standard illuminants provide a basis for comparing images or colors recorded under different lighting. CIE illuminants The Inter ...
C and A data from 1932.


MacAdam ellipses

One of MacAdam's best known contributions was in support of technological color control. Assuming that the basis of color difference perception was the statistical error in matching the appearance of a given color stimulus he conducted an extensive experiment with one observer, the result of which was expressed in the CIE chromaticity diagram in form of statistically derived ellipses, published in 1942 (See Fig. 1).Visual sensitivities to color differences in daylight, ''Journal of the Optical Society of America'', 32, 1942, 247–274. However, the resulting Friele–MacAdam–Chickering color difference formula proved less effective in predicting perceived color differences than formulas derived on other bases. In attempting to convert the ellipses to circles of equal size MacAdam encountered the non- Euclidean nature of psychophysical
color space A color space is a specific organization of colors. In combination with color profiling supported by various physical devices, it supports reproducible representations of colorwhether such representation entails an analog or a digital represen ...
.


Instrumentation and computation

In the mid-1940s MacAdam pioneered the use of computers in colorimetric computations, established Hardy's reflectance spectrophotometer as a reliable industrial measuring instrument, and invented a tristimulus integrator as an accessory.


Principal component analysis of daylight

With
Deane B. Judd Deane Brewster Judd (November 15, 1900 – October 15, 1972) was an American physicist who made important contributions to the fields of colorimetry, color discrimination, color order, and color vision. Education Judd was born in South Ha ...
and Günter Wyszecki, MacAdam performed the first principal-component analysis of phases of daylight of various correlated
color temperature Color temperature is the color of light emitted by an idealized opaque, non-reflective body at a particular temperature measured in kelvins. The color temperature scale is used to categorize the color of light emitted by other light sources ...
s, demonstrating that they can be represented as linear combinations of a limited number of spectral components.


Optical Society of America Uniform Color Scales

MacAdam was a leading member of the committee of the
Optical Society of America Optica (formerly known as The Optical Society (OSA) and before that as the Optical Society of America) is a professional society of individuals and companies with an interest in optics and photonics. It publishes journals and organizes conference ...
that in 1947, at the suggestion of the
U.S. National Research Council The National Academies of Sciences, Engineering, and Medicine (also known as NASEM or the National Academies) are the collective scientific national academy of the United States. The name is used interchangeably in two senses: (1) as an umbrell ...
, began work on a perceptually uniform colorimetric model of the color solid. Upon the retirement of its first chairman D. B. Judd, MacAdam was elected chair. The result of the committee's work was published in 1974 as ‘Uniform Color Scales,’ with OSA publishing a related color atlas with 558 samples in 1977.


Publications

In addition to his contributions to ''Handbook of Colorimetry'' (1936) he was a major contributor to OSA's 1953 book ''The Science of Color''. His interest in the history of color science resulted in publication in 1970 of ''Sources of Color Science'', a compilation of 26 seminal papers on color science, from
Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...
to
Le Gros Clark Sir Wilfrid Edward Le Gros Clark (5 June 1895 – 28 June 1971) was a British anatomist, surgeon, primatologist and palaeoanthropologist, today best remembered for his contribution to the study of human evolution. He was Dr Lee's Professor of ...
, several translated for the first time into English. In 1981 he published ''Color Measurement: Theme and Variations'', a presentation of fields of color science in which he has made important contributions.''Color Measurement: Theme and Variations'', New York: Springer Verlag, 1981 He is also the author of some 100 peer-reviewed journal articles. MacAdam was president of the Optical Society of America in 1963 and editor of the '' Journal of the Optical Society of America'' from 1964 to 1975. He was active in the Inter-Society Color Council and the Commission Internationale de l’Eclairage (CIE). He received honors from many societies, including the Frederic Ives Medal of the Optical Society of America in 1974.


References


See also

* MacAdam ellipse * Optical Society of America#Past Presidents of the OSA *
OSA-UCS In colorimetry the OSA-UCS (Optical Society of America Uniform Color Space) is a color space first published in 1947 and developed by the Optical Society of America’s Committee on Uniform Color Scales. Previously created color order systems, suc ...
{{DEFAULTSORT:Macadam, David 1910 births 1998 deaths Color scientists Optical physicists Fellows of the Optical Society Kodak people People from Upper Darby Township, Pennsylvania Presidents of the Optical Society