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.


eight-degree geometry

irradiation or measurement of reflecting materials at 8° to the normal, at one azimuth angle

Note 1 to entry: Eight-degree geometry is used to substitute the 0° directional geometry in many practical applications of reflection measurements, as it permits differentiation between specular-component-included and specular-component-excluded measurements.

Note 2 to entry: This geometry is restricted to measurements using an integrating sphere as described in CIE 15 Colorimetry.

Note 3 to entry: This entry was numbered 17-363 in CIE S 017:2011.

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