Optical density

Description

The measurement unit for Opacity. Optical density is expressed as the logarithm to base 10 of the reciprocal of transmittance (transmission measurement) or reflectance (reflection measurement).

Synonyms and Related Terms

Schwärzung (Deut.); densité optique (Fr.);

Resources and Citations

• ASTM, Standard Terminology of Microscopy, Annual Book of ASTM Standards, Section 14, General Methods and Instrumentation, ASTM, E175, 75-78, May 1982

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998