Definition
Luminance is defined by the derivative
where
- is the luminance (cd/m2),
- is the luminous flux or luminous power (lm),
- is the angle between the surface normal and the specified direction,
- is the area of the surface (m2), and
- is the solid angle (sr).
The expression is written using Leibniz's notation.
Read more about this topic: Luminance
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