TABLE OF CONTENTS Outdoor lighting is used during darkness to illuminate building entrances and facades, landscaping, walks, parking and security areas, signage, entertainment and recreation areas, landmarks, and the like. Such illumination should promote safety (reveal obstacles such as steps, landings, curbs, walls, pool edges, and belongings left outside), increase security (identify boundaries, reveal entrances, and eliminate hiding places), and enhance aesthetics (accentuate desirable features and increase outdoor enjoyment). The goal is always a pleasing and cohesive visual composition. Outdoor lighting differs from indoor lighting as follows:
Lighting is usually related to utilitarian, recreational, and aesthetic needs more than economics; thus occupancy factors usually equal 1.00.
Lack of enclosing reflective interior surfaces means little ambient light compared to the indoors. Thus precise aim and proper field angles of luminaires are more important.
Contrast is often important. This is prominent at night anyway, and such 'visual syncopation' increases the relative brilliance of the illuminated object. On the other hand, overlighting is especially undesirable outdoors, as it usually appears more garish and unexpected than when indoors.
Light sources should generally be concealed, during the day as well as at night. Not only does this avoid glare, but hiding the light source usually lends mystery to its effect. This is most easily done if luminaires have diffuse lenses, their light bounces off reflective surfaces into adjacent focal areas, and several small lamps are used instead of one large.
Weather extremes and the need for vandal resistance require...
