Discomfort Glare from Several Sources: A Formula for Outdoor Lighting

ABSTRACT

Many models have been developed to predict the discomfort glare generated by one light source in the visual field. Some of them were generalized to predict discomfort glare from several sources, but they were not directly built from multi-source data. In their generalization, they do not consider the potential interactions due to the fact that the light sources are switched on together. In the present work, a psycho-visual experiment was conducted for a better understanding of the glare produced by several sources using a matching task at the Borderline between Comfort and Discomfort (BCD). A formula is proposed to compute the photometric and geometric characteristics of an equivalent source which generates the same level of discomfort glare as several sources switched on together. This formula is the first step towards a multi-source model of discomfort glare. The practical implications are discussed.

KEYWORDS:

• Discomfort glare
• LED
• multi-source
• psychophysics
• outdoor lighting

Acknowledgments

The authors would like to thank Eric Dumont for his contributions and helpful advice, and all the participants who took part in the experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors report no funding.