1988 Volume 72 Issue 10 Pages 613-619
Limitation of discomfort glare from a lighting installation is one of the important factor for comfortable lighting.
In order to clear the preferable condition of luminance on lighting installation, it is important to establish the criterion for discomfort glare evaluation from the light source not only in the peripheral vision but also in the central vision. However, the experiments were insufficient in the former studies, accordingly the experimental study using subjective appraisal related to discomfort glare was carried out in this paper.
As a result, authors give a formula for calculating the glare effect, as follows:
Glare degree (Gi)=k [1.407 log Ls+ {0.0390 (logω) 2+0.439 log ω-2.09}-log Lb+c]
Where Ls=source luminance (cd/m2)
Lb=surround luminance (cd/m2)
ω=apparent area of source (sr)
k, c=constants
Substituting k=9 and c=3 in the formula, the subjective ratings is expressed in a scale which may be translated as:
severe glare...30
considerable glare...27
slight glare...22
