trolandn.
/ˈtrəʊlənd/ A unit of retinal illumination, being the illumination produced by a surface with a luminance of one candela per square metre when the pupil has an area of one square millimetre; originally called a photon (photon n.1 1).
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troland1944
1944 Jrnl. Optical Soc. Amer. 34 254/2 [Report by the Committee on Colorimetry.] A special unit of retinal illuminance, the photon, was introduced by Troland in 1917 and has been employed to some extent, but its use is circumscribed by the danger of confusion with the elementary quantum of radiant energy which is generally called the photon. The renaming of the unit of retinal illumination as the troland, in honor of Dr. L. T. Troland, its originator and chairman of the Committee..in 1921–22, is recommended.
1976 Nature 19 Feb. 570/1 We have..measured sensitivity to short wavelengths after adaptation to retinal illuminances that varied over the range 1·1–6·0 log trolands.
This entry has not yet been fully updated (first published 1986; most recently modified version published online March 2019).
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