colour.luminous_efficacy#

Compute the luminous efficacy in \(lm\cdot W^{-1}\) of the specified spectral distribution using the specified luminous efficiency function.

Luminous efficacy quantifies how effectively a light source converts radiant power into luminous flux as perceived by the human visual system.

Parameters:

sd (SpectralDistribution) – Test spectral distribution to evaluate.
lef (SpectralDistribution | None) – \(V(\lambda)\) luminous efficiency function, defaults to the CIE 1924 Photopic Standard Observer.

Returns:

Luminous efficacy in \(lm\cdot W^{-1}\).

Return type:

float

References

Examples

>>> from colour import SDS_LIGHT_SOURCES
>>> sd = SDS_LIGHT_SOURCES["Neodimium Incandescent"]
>>> luminous_efficacy(sd)
136.2170803...