Exposure (physics)
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Surname | exposure | ||||||
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The lighting size of the exposure ( English luminous exposure ) is defined as the period of time over a given total received light amount per surface element . Equivalent to this is the definition as the (integrated) illuminance added up over the period :
- .
The exposure is inversely proportional to the exposure index . Your unit of measurement is the lux second , lx · s .
The radiometric equivalent of exposure is exposure .
Reference to other photometric and radiometric quantities
radiometric quantity | Symbol a) | SI unit | description | photometric equivalent b) | symbol | SI unit |
Radiant flux radiant power, radiant flux, radiant power |
W ( watt ) |
Radiant energy through time |
Luminous flux luminous flux, luminous power |
lm ( lumens ) |
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Radiant intensity irradiance, radiant intensity |
W / sr | Radiation flux through solid angles |
Luminous intensity luminous intensity |
cd = lm / sr ( candela ) |
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Irradiance irradiance |
W / m 2 | Radiation flux through the receiver surface |
Illuminance illuminance |
lx = lm / m 2 ( lux ) |
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Specific radiation emission current density, radiant exitance |
W / m 2 | Radiation flux through the transmitter surface |
Specific light emission luminous exitance |
lm / m 2 | ||
Radiance radiance, radiance, radiance |
W / m 2 sr | Radiant intensity through effective transmitter area |
Luminance luminance |
cd / m 2 | ||
Radiant energy amount of radiation, radiant energy |
J ( joules ) |
by radiation transmitted energy |
Amount of light luminous energy, quantity of light |
lm · s | ||
Irradiation irradiation, radiant exposure |
J / m 2 | Radiant energy through the receiver surface |
Exposure luminous exposure |
lx s | ||
Radiation yield radiant efficiency |
1 | Radiation flux through absorbed (mostly electrical) power |
Luminous efficiency (overall) luminous efficacy |
lm / W |
a)The index "e" is used to distinguish it from the photometric quantities. It can be omitted.
b)The photometric quantities are the radiometric quantities, weighted with the photometric radiation equivalent K , which indicates the sensitivity of the human eye.
literature
- Horst Stöcker: Pocket book of physics. 4th edition, Verlag Harry Deutsch, Frankfurt am Main, 2000, ISBN 3-8171-1628-4