Editing Luminous intensity (section)

==Measurement==
Photometry deals with the measurement of visible light as perceived by human eyes. The human eye can only see light in the [[visible spectrum]] and has different sensitivities to [[light]] of different wavelengths within the spectrum. When adapted for bright conditions ([[photopic vision]]), the eye is most sensitive to yellow-green light at 555&nbsp;nm. Light with the same [[radiant intensity]] at other wavelengths has a lower luminous intensity. The curve which represents  the response of the human eye to light is a defined standard function {{math|{{overline|''y''}}(λ)}} or {{math|''V''(λ)}}  established by the [[International Commission on Illumination]] (CIE, for ''Commission Internationale de l'Éclairage'') and standardized in collaboration with the [[International Organization for Standardization|ISO]]. <ref>{{cite book | url=https://www.iso.org/standard/83178.html | title=ISO/CIE 23539:2023 CIE TC 2-93 Photometry — The CIE system of physical photometry | publisher=ISO/CIE | date=2023 | language=en | doi=10.25039/IS0.CIE.23539.2023}}</ref>

Luminous intensity of artificial light sources is typically measured using and a [[goniophotometer]] outfitted with a [[photometer]] or a spectroradiometer. <ref>{{cite book |last1=Schneider |first1=T. |last2=Young |first2=R. |last3=Bergen |first3=T. |last4=Dam-Hansen |first4=C |last5=Goodman |first5=T. |last6=Jordan |first6=W. |last7=Lee |first7=D.-H |last8=Okura |first8=T. |last9=Sperfeld |first9=P. |last10=Thorseth |first10=A |last11=Zong |first11=Y. |title=CIE 250:2022 Spectroradiometric Measurement of Optical Radiation Sources |date=2022 |publisher=CIE - International Commission on Illumination |location=Vienna |isbn=978-3-902842-23-7 |url=https://orbit.dtu.dk/en/publications/cie-2502022-spectroradiometric-measurement-of-optical-radiation-s}}</ref>
{{SI light units}}