colour_hdri.exposure_value

colour_hdri.exposure_value(f_number, exposure_time, iso, k=12.5)[source]

Computes the average illuminance in \(Lux\) from given image F-Number \(N\), Exposure Time \(t\) and ISO speed \(S\) and reflected light calibration constant \(k\).

Parameters:
  • f_number (array_like) – Image F-Number \(N\).
  • exposure_time (array_like) – Image Exposure Time \(t\).
  • iso (array_like) – Image ISO \(S\).
  • k (numeric, optional) – Reflected light calibration constant \(k\).
Returns:

Image exposure value.
Return type:

ndarray

Examples

>>> exposure_value(8, 1, 100)
6.0