Possibility of Daylight Simulators Composed of Several Monochromatic Radiations

Abstract

The possibility of realizing daylight simulators satisfying the conditions specified in JIS Z8720-1983 and Publication CIE No. 51, with line spectrum sources composed of several monochromatic radiations (lines), was examined by a nonlinear programming technique. It was found possible to realize simulators satisfying: (1) the condition of a visible range metamerism index Mlvis ≤ 0.5 (CIELAB10) with 5 spectral lines, (2) the condition of an ultraviolet range metamerism index Mluv ≤ 1 (CIELAB10) with 3 lines, (3) both Mlvis ≤ 0.5 and Mluv ≤ 1,while the general color rendering index Ra is not sufficiently high, with 6 lines, (4) Ra ≥ 95 (CIE 2nd Edition), while Mlvis is not sufficiently good, with 5 lines, and (5) Mlvis ≤ 0.5,Mluv ≤ 1 and Ra ≥ 95 with 7 lines. (6) Six lines are necessary to realize both Mlvis ≤ 0.5 and Ra ≥ 95, in contrast with 5 lines in cases (1) and (4). It is suggested that daylight simulators in either case (5) or (6) are insufficient to reproduce the color appearance of chromatic fluorescent objects excited by visible range radiation under a natural daylight illuminant.