
British Museum, London

Ezeiza Airport, Buenos Aires

Eremitage, St. Petersburg

Villa, Salzburg
Indirect general lighting uses a ceiling, wall or other surface as a secondary reflector. The brightening of these surfaces that delineate the room or area gives an open spatial impression.
The diffuse light produces limited shadows and a weak modelling. Shapes and surface textures are only slightly emphasised. Using indirect illumination alone gives a lower spatial differentiation. Compared to direct illumination, a considerably higher luminous flux is necessary for achieving the same illuminance on the working plane. The secondary reflector should boast a high reflectance. Direct and secondary glare are extensively avoided.
The prerequisite for an even distribution of light is a sufficiently high room. Indirect illumination should be mounted above eye-level. The distance from the ceiling depends on the level of evenness required and should be at least 0.8 m.
Indirect general lighting for:
Direct/indirect general lighting refers to a combination of direct and indirect illumination with respect to the horizontal working plane. The ceiling or walls serve here as reflection surfaces. The brightening of these surfaces that delineate the room or area gives an open spatial impression.
The uniformity on the working plane improves as the room height increases. Directed light enables a good appreciation of form and surface texture. The secondary reflector should boast a high reflectance. The uniformity on the ceiling increases the further away the luminaire is from the ceiling. A feature of general lighting with fluorescent lamps is its highly efficient use of energy.
Direct/indirect general lighting for
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