The experiment provided a situation in which identical reproductions of artworks were
presented in two adjacent simulated art gallery settings, one being the test situation and the
other the comparison situation. Subjects adjusted the illuminance in the test situation, which
was illuminated alternately by an MR lamp and an experimental 3-band light source, to match
the appearance of the comparison situation. The comparison situation was always illuminated
to 50 lux by an MR lamp. The settings were recorded and compared to see whether there were
differences in the illuminances that subjects selected to achieve similar appearances.
Differences of irradiance were calculated from the recorded illuminances. Also, subjects were
questioned on any differences of appearance they noticed after making each setting.