Abstract
The possibility of realizing daylight simulators satisfying the conditions specified in JIS Z 8720-1983 and Publication CIE No.51, with line spectrum illuminants composed of several monochromatic radiations (lines), was examined by a nonlinear programming technique.
It was found possible to realize sinulators satisfying:
(1) the condition of a visible range metamerism index MIuv ≤ 0.5 (CIELAB10) with 5 spectral lines,
(2) the condition of an ultraviolet range metamerism index MIuv ≤ 1 (CIELAB10) with 3 lines,
(3) both MIuv ≤ 0.5 and MIuv ≤ 1, while the general color rendering index Ra is not sufficietly high, with 6 lines,
(4) Ra ≤s 95 (CIE 2nd Edition), while MIuv is not sufficietly good, with 5 lines, and
(5) MIuv ≤ 0.5, MIuv ≤ 1 and Ra ≥ 95 with 7 lines.
(6) Six lines are necessary to realize both MIuv ≤ 0.5 and Ra ≥ 95, in contrast with 5 lines in cases (1) and (4).
These results show that the general color rendering index is a different measure from the metamerism index, and useful to supplement the latter for the assessment of daylight simulators. However, it is suggested that daylight simulators in eithr 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.
