Sensitometry

Page 10 of Raymond Davis Jr. and F. M. Walters, Jr., Scientific Papers of the Bureau of Standards, No. 439 (Part of Vol. 18) "Sensitometry of Photographic Emulsions and a Survey of the Characteristics of Plates and Films of American Manufacture," 1922. The next page starts with the H & D quote: "In a theoretically perfect negative, the amounts of silver deposited in the various parts are proportional to the logarithms of the intensities of light proceeding from the corresponding parts of the object." The assumption here, based on empirical observations, is that the "amount of silver" is proportional to the optical density.

Sensitometry is the scientific study of light-sensitive materials, especially photographic film. The study has its origins in the work by Ferdinand Hurter and Vero Charles Driffield (circa 1876) with early black-and-white emulsions.[1][2] They determined how the density of silver produced varied with the amount of light received, and the method and time of development.

  1. ^ Hurter, Ferdinand & Driffield, Vero Charles (1890) Photochemical Investigations and a New Method of Determination of the Sensitiveness of Photographic Plates, J. Soc. Chem. Ind. May 31, 1890.
  2. ^ Mees, C. E. Kenneth (May 1954). "L. A. Jones and his Work on Photographic Sensitometry" (PDF). Image, Journal of Photography of George Eastman House. III (5). Rochester, N.Y.: International Museum of Photography at George Eastman House Inc.: 34–36. Archived from the original (PDF) on 20 July 2014. Retrieved 15 July 2014.