illumination (Beleuchtung)

Illumination describes an optical (i.e. visible for humans) brightening of things by light.

There is natural illumination (e.g. by the sun) as well as artifical illumination performed by flood lights or luminaires.

opsira GmbH develops customized solutions for optimized illumination and delivers test systems for production control as well as for the use in labs for the analysis of illuminance distributions.

You will find further information on illumination here. 

q.v.: illuminance