| Title |
A Study on the Change of Brightness Perception on Different Spectral Characteristics of the Light Source : the evaluation of brightness perception on the change of visual field |
| Keywords |
Fluorescent Lamp ; Spectral Characteristics ; Luminance ; Brightness Perception |
| Abstract |
The objective of this paper is to examine the effect of different spectral characteristics of the light source and luminance levels on the human brightness perception in a building interior. The following psychological tests were conducted. The perception or room brightness on the change of visual field over photopic luminance ranging from 100cd/㎡ to 300cd/㎡ was measured for 12 subjects using a pair of experimental chambers. The daylight, warm white, daylight 3band-type fluorescent lamps were used as lighting sources. One experimental chamber was lit by daylight fluorescent lamps and the other chamber was lit by one of the other two fluorescent lamps. Two different fluorescent lamps were studied and the subjects were judged to rate their brightness perception. And they were requested to adjust luminance level on one chamber to get equal brightness with the other. Ratio of luminance by comparing lamps with daylight lamps were calculated.
The following results were obtained :
For all most subjects, the differences of brightness perception between daylight fluorescent lamp and the other lamps were not appeared on 2。visual field. However the ratio 1.22 and 0.89 were determined for the warm white and daylight 3band-type fluorescent lamps, respectively, to obstain the equal perceived brightness at luminance level 100cd/㎡. The ratio decreases with a rise in luminance level 200～300cd/㎡ on 10。visual field. It became clear that not only photopic luminance but also scotopic luminance contributes to perceped brightness in according with luminance levels. |