Intensity of Stage lighting
Measured in lux, lumens and foot-candles. For any given luminaire (lighting instrument or fixture), this depends upon the power of the lamp, the design of the instrument (and its corresponding efficiency), the presence or absence of colour gels or gobos, distance from the area to be lit and the beam or field angle of the fixture, the colour and substance to be lit, and the neuro-optics of the total scene (that is, the relative contrasts to other regions of illumination).