2019 Volume 103 Issue 10 Pages 413-420
The purpose of this study was to design spectral power distributions of light sources while considering the color appearance and preservation of artwork under low illuminance by using a “color quality index” called Gx(E). One of the spectral distributions obtained from theoretical calculations was reproduced by using a lighting device with six types of monochromatic LEDs. Subjective evaluation experiments were conducted under various light sources, and the prediction accuracy of Gx(E) was verified.
Theoretical and subjective evaluation of the experiment revealed the following results: (1) The spectral power distribution with the maximum Gx(E) at 10 lx was a narrow band distribution with red (630 nm), green (530 nm), and blue (470 nm), and it was called LED-RGB. (2) The subjective evaluation results corresponded well with Gx(E), so Gx(E) could be used to design spectral power distributions of museum lighting at a low illuminance. (3) The damage coefficient of LED-RGB was the same or smaller than that of fluorescent and halogen lamps.
We concluded that an LED-RGB with 630 nm, 530 nm, and 470 nm had the maximum Gx(E), and it was an advantageous spectral distribution for art appreciation under low illuminance for the aspects of color appearance and damage.
