Sizing an installation MIROS lighting design
MIROSLIGHTING DESIGN 16 Distance between projector and surface to be illuminated
This diagramcan be used to roughly esti-mate the mean illuminance levels in thelight coneof the reflector depending onthe distance to the mirror surface. Theselevels can be determined for three diffe- rent types of multi-faceted mirror (beamdivergence of cone: 2 x 10°, 2 x 20°, 2 x 30°). The following assumptions are made for the sake of simplification:• Light loss factor 0.8 (ageing, dirt)• No allowance made for light conedistortion• Assumed spill by projector 30 %• Projector model 150 W CDM - SA/T• Highly specular mirror The diagramon the right showsthe approximate diameter of thelight cone as a function of thebeam divergence of the mirror and the distance between the mirror and the floor. This isbased on a projector with a 1/10angle of diffusion of 5–7º.