An optical source emits a luminous flux (F) of energy toward a sensor. This flux propagates from the source to the sensor.
Relationships between luminous parameters are summarized into the below table:
Luminance is a quantity representing the brightness of sources independently from its size and its emitting cone. This value is consequently often used to compare tow sources.
The USI unit of luminous flux is Lumen, abbreviation lm.
1 lumen = 1/683 Watt at 555 nm
555 nm is the wavelength to which the eye is the most sensitive.
The USI unit of luminous intensity is Candela, abbreviation cd.
1 cd = 1 lm/sr
1sr = 1 steradian is the cone of light spreading out from the source which would illuminate 1 m² at 1 m distance from the source.
The USI unit of luminance or Radiance is Candela per square meter, abbreviation cd/m².
Other units are available:
The USI unit of illuminance or irradiance is Lux, abbreviation lx.
1 lux = 1 lm/m²
Other units are available:
HGH is a electro-optical devices global provider. The company provides wide area surveillance, industrial thermography and electro-optical test solutions.
HGH est une référence internationale dans la surveillance de sites étendus, la thermographie industrielle et les applications de test électro-optiques infrarouges.
