Light-Vocabulary

__**General Electrics**__

**Bayonet** A style of bulb base which uses keyways instead of threads to connect the bulb to the fixture base. The bulb is locked in place by pushing it down and turning it clockwise. **Candlepower** An obsolete term for luminous intensity; current practice is to refer to this simply as candelas. **Cathode** Metal filaments that emit electrons in a fluorescent lamp. Negatively charged free electrons emitted by the cathode are attracted to the positive electrode (anode), creating an electric current between the electrodes.

**Flood** Used to refer to the beam pattern of a reflector lamp, which disperses the light over a wide beam angle, typically 20 degrees or more.

__**Pegasus Associates Lighting**__

**Bulb** A colloquial term for a lamp. In the lighting industry, the term, bulb, refers only to the glass envelope of the lamp. Some lighting professionals contemptuously refer to "bulbs" as those things that are planted in the ground **Dimmer** A device in an electrical circuit used for varying the brightness of lamps in a lighting installation. Dimming controls are ideal for almost any type of room because they can change the amount of lighting to suit each mood or activity and they can help you look good. **Glare** Direct glare is caused by light coming directly to the eye from a light source. Indirect glare is light reflected from a surface in the direction of the eye. Both can harm vision and cause visual discomfort or disability. **Sconce** An ornamental light fixture attached to a wall. Synonym: wall sconce