CIE 018:2019介绍了物理光度学的基本惯例和原理，以及国际单位制（SI）2019中重新制定的光度学单位的定义，以及明视、中视和暗视（包括10°明视）的光度量和光谱发光效率函数。描述了基于常数Kcd的光度量和辐射量之间的关系，以及光化学量和光生物量与光度量之间的关系。介绍了色度学的惯例，以及2°和10°视场的颜色匹配函数、三刺激值和色度坐标的定义。

CIE 018:2019 presents the basic conventions and principles of physical photometry, with the definitions of the photometric units as reformulated in the International System of Units (SI) 2019 and the photometric quantities and spectral luminous efficiency functions for photopic, mesopic and scotopic vision, including 10° photopic vision. The relationships between the photometric quantities and the radiometric quantities based on the constant Kcd are described, as well as the relationships between photochemical and photobiological quantities and photometric quantities. The conventions of colorimetry are presented, with the definitions of the colour-matching functions for the 2° and 10° field of view, tristimulus values, and chromaticity coordinates.