Brilliance
the brilliance L (English. luminance) is the photo-metric measure for brightness. A source of light appears thus all the brighter, the smaller their surface in the comparison to luminous intensity to I is. The brilliance is what humans notice as brightness.
To table of contents |
definition
with the brilliance concerns it the relationship of radiated luminous intensity I and the quantity Atheir apparent bright surface. The brilliance has the unit candela per meter ² and/or. cd/m ². It is photo-metric correspondence to the radiation intensity L (λ) (unit: Watt·Meter of -2·Steradiant -1 and/or. W·m -2·SR -1) of the radiometry.One does not see perpendicular on the radiating surface, only its projection is effective (angles θ).
characteristic shining densities
brightness of the sky
- of middle ones clear sky: 8000 cd/m ²
- middle ones covered sky: 2000 cd/m ²
- Night sky with full moon: 0,1 cd/m ²
- star-clear night sky: 0,001 cd/m ²
- cloudy night sky: 1… 100 · 10 -6 cd/m ²
- perception border: 3 · 10 -6 cd/m ²
Flächenhelligkeit of emitters
- sun disk at noon: 1600 · 10 6 cd/m ²
- sun disk on the horizon: 6· 10 6 cd/m ²
- mat bulb 60 W: 120 · 10 3 cd/m ²
- T8 cold-white fluorescence tube: 11 · 10 3 cd/m ²
- surface of the moon: 2,5 · 10 3 cd/m ²
- the Greens elektrolumineszente source of light: 30 cd/m ²
units
into that The USA are the units Lambert and/or. the name of rivet for candelas per square meter common.
Older units of the brilliance are among other things:
- Rivet: 1 NT = 1 cd/m ²
- Stilb: 1 self-service = 1 cd/cm ² = 10,000 cd/m ²
- candelas per square foot: 1 cd/ft ² = approx.10,764 cd/m ²
- candelas per square tariff: 1 cd/in ² = approx. 1.550 cd/m ²
- Apostilb, Blondel: 1 asb = 1 blondel = 1/π · 10 -4 self-service = 1/π cd/m ²
- Skot: 1 skot =0,001 blondel = 0.001 asb = 10 -3/π cd/m ²
- Lambert: 1 la = 1 L = 10/π cd/m ² = approx. 3,183 cd/m ²
- Footlambert: 1 flat steel bar = 1/π cd/ft ² = approx. 3,426 cd/m ²
