Raymond Davis passed away, in his sleep, in the early morning of September 5, 1974, at his home in Washington, DC. He was 86 years old and nationally recognized for his contributions to photographic sensitometry, colorimetry, and microphotography.
Davis joined the National Bureau of Standards (NBS) as a photographer in 1911. By 1917, he was constructing equipment for the evaluation of photographic materials. He was an ingenious designer and often made his own apparatus. He insisted on "doing it right the first time," and when a job was done, he would stand back, puff his pipe, watch the thing work, and enjoy the fulfilling sense of satisfaction that only a true craftsman knows. His time-lapse motion picture camera, with automatic exposure control, photographed the construction of the Industrial Building at the National Bureau of Standards in 1918.
By that time he had measured spectrosensitivities, the resolving powers, and several sensitometric characteristics of all available American negative materials. The Photographic Technology Section was established in 1920, with Davis as Chief. In the mid-1920s, this group put forth a standard light source for sensitometry so that laboratories could compare sensitometric evaluations on a liquid filter that was adopted but internationally for sensitometry. In 1931, Davis-Gibson filters were adopted by the International Commission on Illumination for use in photometry and colorimetry. The Davis-Gibson filters are used to this day in national and international standard light sources.
Davis introduced the concept of "correlated color temperature" to characterize light sources of nearly Planckian spectral distribution. This is an indispensable concept in modern photography, lighting practice, and colorimetry.
Until 1932, The Federal Bureau of Investigation relied on NBS for scientific support and Davis was an important contributor to their investigations. He invented an ingenious technique for photographing the entire cylindrical surface of a bullet, as a continuous photograph on a single film, as well as a remarkably unusual application of the photographic process for the recovery of information from documents charred beyond legibility by fire. He also assisted in the scientific analysis of evidence related to the kidnapping of Charles A. Lindbergh’s son.
In the early 1930s, NBS did a lot of research on microfilm for archival purposes. Congress enacted a law permitting the destruction of federal paper records if they had been copied on film meeting the standards of NBS. Davis played a role in that research and was responsible for implementing the law.
To meet the demand on the short supply of handmade reticles and precisely graduated circles for navigational and fire control instruments, Chester Pope and Davis developed a new light-sensitive resist for producing such scales on glass by photoetching. No one dreamed at that time that these techniques were to be further developed and be widely used in the production of microminiature electronic components. In Davis’s lifetime this technology paved the way to man’s exploration of the moon, instrumental exploration of the planets, revolutionary advances in aircraft instrumentation, and the development of inexpensive miniature computers.
He helped establish the standardization of photographic materials and processes in the American Standards of Association, predecessor of the American National Standards Institute. From 1938 until his retirement in 1958, he was very active in nearly every facet of national photographic standardization and he continued to participate in this arena after he retired as a representative of the Optical Society of America (OSA). He also represented the United States at the meetings of the Photography and Cinematography Committees of the International Organization for Standardization, in England, in 1958. He was a soft-spoken and modest man, but stood courageously for doing things right and argued persistently and persuasively for his position on standards.
He was a Charter member and the first President of the Society of Photographic Engineers, founded in January 21, 1947. The Society merged with the Technical Section of the Photographic Society of America in 1957, to become the Society of Photographic Scientists and Engineers (SPSE), later IS&T. He was one of the first two Fellows of SPSE—along with John A. Maurer—having been awarded that honor in 1954. He was a Fellow of OSA and the Washington Academy of Sciences; a member of the American Chemical Society, International Congress of Photography, Philosophical Society of Washington, and Chemical Society of Washington; and a founders of the Federal Photographers. He was a Registered Engineer in the District of Columbia.
He left behind a wife, Dr. Marian MacLean Davis, a well-recognized authority on the chemistry of acids and bases in inert solvents; two sons: Dr. Raymond Davis, Jr., and Col. Warren Davis; and eight grandchildren.