[1] In 1927, Judd joined the National Bureau of Standards' permanent staff where he remained until his retirement in 1969 and subsequently continued as a guest worker.

When in 1947 at the suggestion of the U.S. National Research Council the Optical Society of America (OSA) undertook to develop a perceptually uniform color space, Judd became its chairman and remained in that position until 1968, when David L. MacAdam assumed the chairmanship, with results published in 1974.

[7] Miscellaneous: In connection with his work at NBS, Judd investigated impaired color vision, whiteness measurement of paper, opacity, color stimulus measurement, a flattery index for artificial light sources, and other subjects.

[8] In addition to his positions at the CIE, Judd was president of the Optical Society of America from 1953–1955 and of the Inter-Society Color Council from 1940-1944.

He received numerous awards over his career, including the Optical Society's highest honor, the Frederic Ives Medal in 1958.