Luminance

The term luminance is used when talking about how illuminated objects appear to an observer.

  • Luminance is a measure of the intensity of light that reaches the eye.
  • So we can talk about:
    • The luminance desert sand under moonlight.
    • The luminance of a road surface under street lights.
    • The luminance of a book cover in sunshine.
  • Luminance can be measured and so is an objective term rather than a subjective experience.
  • The light produced by a table lamp can be described in terms of luminosity, the amount of light that is then reflected from a surface towards an observer can then be measured in terms of luminance.

https://en.wikipedia.org/wiki/Luminance