Cylindrical Illuminance
This page describes how Cylindrical Illuminance is calculated.
On the following example, the source is simulated by a local point source.
Note:
The source can also be an extended light source like luminaire, ambient, surface source, etc.
The sensor is sensible to light coming from all directions except the direction exactly normal to the sensor plane.
The cylindrical illuminance can be defined by the specific case of vertical illuminance (when α = 0°).
Because of the rotational symmetry (around z axis) only the angle ε is important. In that case, you do not need a specific integration direction.
The formula is _Sensor_Irradiance_Cylindrical_Illuminance_01.png)
_Sensor_Irradiance_Cylindrical_Illuminance_01.png)