Unit of measure : candela per m² (cd/m²)


Luminance is the basic luminance perceived by the human eye. It is decisive for the impression of brightness of a luminous or illuminated surface.


Luminance L is defined by the luminous intensity Iε of an area A in the direction ε


A * cos ε is the "seen area" from direction ε



If diffuse reflection (Lambert radiators) is assumed for an illuminated surface, a simple relationship between luminance L and illuminance E of this surface results:


ρ = reflectance of the surface


The distribution of luminance between various surfaces in an illuminated interior is an important criterion for the quality of the visual experience. A balanced and harmonious distribution of brightness makes a room pleasant and visually interesting (cf. Brightness, Contrast, Uniformity).


Typical examples of luminance:

 

cd/m²

Sonne je nach Sonnenstand

600.000 ... 1.600.000.000

Glühlampe matt

20.000 ... 50.000

Kompakt-Leuchtstofflampe

9.000 ... 25.000

Leuchtstofflampe

4.000 ... 17.000

Arbeitsgut im Büro

100 ... 200

Bildschirme

20 ... 200

Umfeld im Büroraum

10 ... 100