cie

e-ILV

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.

For advice on CIE Publications contact helpdesk@cie.co.at. Note the CIE Helpdesk cannot assist with technical enquiries.

17-25-090

(C, γ) coordinate system

coordinate system commonly used in the photometry of luminaires in which the C-planes are half-planes that rotate round the vertical line through the photometric centre of the luminaire, and the γ-angles are measured up to 180° from the direction of the perpendicular to the rotation axis of the C-planes

Note 1 to entry: Other coordinate systems [(A, α) coordinate system and (B, β) coordinate system] exist as well. See CIE 121 The Photometry and Goniophotometry of Luminaires.

Note 2 to entry: This entry was numbered 17-116 in CIE S 017:2011.

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