# 17-25-098

first axis, <of a luminaire when measured in the (C, γ) coordinate system>

vertical axis through the photometric centre of a luminaire when it is at its tilt during measurement

Note 1 to entry: The poles of the (C, γ) coordinate system lie in this axis.

Note 2 to entry: The first axis is tilted when the attitude of the luminaire is changed from its attitude during measurement.

Note 3 to entry: See CIE 121 The Photometry and Goniophotometry of Luminaires for more information on the first axis of a luminaire.

Note 4 to entry: This entry was numbered 17-436 in CIE S 017:2011.

Publication date: 2020-12