## luminance

https://doi.org/10.1351/goldbook.L03640
Photometric counterpart of radiance, producing the visual sensation called brightness. Typical units are: $$\text{candela}\ \text{m}^{-2}$$($$\mathrm{nit}$$),$$\text{candela}\ \text{cm}^{-2}$$($$\mathrm{stilb}$$),$$\mathrm{foot}\ \mathrm{lambert}$$ ($$2.426\ \text{nit}$$). As with all photometric quantities, luminance does not refer to a specific wavelength, but applies to light emitted by a standard source (formerly a 'standard international candle', now a blackbody radiator emitting at the temperature of solidifying platinum, $$2042\ \text{K}$$). Conversion from photometric units to radiometric units (e.g. $$\text{J s}^{-1}$$) requires convolution over wavelength of the relative spectral response of the human eye (photopic response tables).
Source:
PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2199 (https://doi.org/10.1351/pac199062112167)