Illumination ¹⁾

Daylight Sunlight Skylight Moonlight Candelight

Incandescent lamps Halogen lamps Photoflood lamps Xenon light 
Fluorescent lamps Mercury-vapor lamps Sodium-vapor lamps

Only in a few rare cases does the light source used for illumination itself provide the subject of a shot. Thus, illumination mainly consists of light reaching film indirectly via the subject. Light from the light source is greatly altered as a result and considerably reduced in power. Illumination may produce color casts if certain colors predominate. For this reason, one should take careful account of the object's surroundings to check whether particular colors predominate when working wiht color film.

Color correction filters are especially helpful in dealing with color castes.
Atmospheric conditions, too, caused by humidity, haze and altitude of the sun, greatly influence illumination of landscape shots.


Fig 1: Light sources

Fig. 1 shows the energy distribution for some characteristic light sources according to wave-length. Distribution of energy is not directly related to brightness of illumination. Thus, there can be stronger rand weaker light of the same spectral composition.