The e-ILV provides free access to all the terms and definitions contained in the international standard CIE S 017:2020 ILV: International Lighting Vocabulary, 2nd edition.

To search for another term please use  "Back to the list" to return to the main page or the e-ILV.

For the complete set of terms and definitions CIE S 017:2020 can be purchased from the CIE Webshop. Members of a CIE National Committee or Associate National Committee have access to a 66,7 % discount on the purchase price of the standard.


luminance difference threshold


smallest perceptible difference in luminance of two adjacent fields

Note 1 to entry: A field superimposed on a second larger field (background) can also be taken as two adjacent fields.

Note 2 to entry: The value of the luminance difference threshold depends on the methodology, luminance, and on the viewing conditions, including the state of adaptation.

Note 3 to entry: The luminance difference threshold is expressed in candela per square metre (cd·m−2 = lm·m−2·sr−1).

Note 4 to entry: This entry was numbered 845-02-46 in IEC 60050-845:1987.

Note 5 to entry: This entry was numbered 17-715 in CIE S 017:2011.

Publication date: 2020-12
Copyright © CIE 2020. All Rights Reserverd.