Outdoor Lighting Glossary

Come across a lighting word you aren't sure of? Completely new to the world of lighting? We feel your pain! Here you will find a collection of terms and concepts that should help to make your life easier.

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Select the first letter of the word from the list above to jump to appropriate section of the glossary.

Baffle - An opaque or translucent element that serves to shield a light source from direct view at certain angles, or serves to absorb unwanted light

Ballast - An auxiliary electrical device consisting of induction windings wound around a metal core and sometimes including a capacitor for power correction. It is used with fluorescent and HID lamps to provide the necessary starting voltage and to limit the current during operation.

Ballast Factor - The ratio of lamp lumen output on a particular ballast as compared to that lamp's (lamps') rated lumen output on a reference ballast under ANSI test conditions (free, unmoving air at 25° C)

Base - The end of the lamp that inserts into lamp socket; The end (or ends) of a lamp that makes electrical and mounting connections with the luminaire.

Batwing Distribution - Candlepower distribution which serves to reduce glare and veil reflections by having its maximum output in the 30° to the 60° zone from the vertical and with a candlepower at nadir (0 degrees) being 65% or less than maximum candlepower. The shape is similar to a bat's wing.

Beam Component - That component of flux received directly (or by specular reflection or transmission) from a point source (such as the sun or small lamp). It is a direct component.

Beam Spread - The angle enclosed by two lines which intersect the candlepower distribution curve at the points where the candlepower is equal to ten percent of its maximum.

Blackbody - A theoretical body used by the lighting industry as a standard for establishing the "color" and spectral qualities of lamps. A perfect blackbody, when its temperature has risen to 3500K would give out light of a certain color; at 4500K it would give a whiter color, and at 5500K a still whiter color.

Blinding Glare - Glare that is so intense that, for an appreciable length of time after it has been removed, no object can be seen.

Brightness - The degree of apparent lightness of a surface: its brilliancy; concentration of candlepower. Brightness is produced by either a self-luminous object, by light energy transmitted through objects or by reflection. Unit of measurement of brightness is the footlambert. (fl). Luminance.

Bulb - The outer jacket or envelope of a lamp.

Bulb Darkening - The darkening of an incandescent lamp caused by small particles of tungsten that evaporate from the filament and deposit on the bulb as the filament burns.

Burning Position - The position in which lamps are designed to he objected.

BX Cable - A cable comprised of a flexible metallic covering inside of which are two or more insulated wires for carrying electricity.