Uniformity of lighting

Uniformity of lighting depends on the type and arrangement of the luminaires, on the geometry of the lighting system and on the type of surfaces being illuminated. Local uniformity of lighting is important for comfort and visual performance. Uneven luminance and illuminance can lead to camouflage zones in which there is inadequate contrast between objects and their surroundings, and because our eyes have to adapt and re-adapt often, they tire quickly.

Uniformity of luminance Local uniformity can be determined from luminance values Lmin, Lmax and Lm, where Lmin is the minimum luminance in the entire assessment field, Lmax is the maximum luminance in the entire assessment field and Lm is the average luminance in the entire assessment field. The following two formulae are used:

The following values are recommended according to DIN 5044 for longitudinal uniformity glo and lateral uniformity gla: A,D very good; B,E good; C,F satisfactory Stage Uniformity glo gloin the longitudinal direction Lmin / Lmax Stage Uniformity gla glain the lateral direction Lmin / Lmax   recommended permitted   recommended permitted A 1:1,3 1:1,6 D 1:2,5 1:4,0 B 1:1,6 1:2,0 E 1:4,0 1:6,0 C 1:2,0 1:2,5 F 1:6,0 1:8,0

Uniformity of illuminance This is indicated by two variables (see also DIN 5035/2). Bmin is the minimum illuminance in the entire assessment field, Bmax is the maximum illuminance in the entire assessment field and Bm is the average illuminance in the entire assessment field.   and    or