Lighting Glossary
Lamp the lightbulb itself
Fitting the appliance the lamp fits into, often informally called a lamp.
CRI Colour rendering index. How well light renders colours. One measure of light quality. 100 is perfect CRI, 50 is poor. However CRI is not the only determinant of colour rendition, CCT matters too.
CCT Colour temperature. A measure of light's perceived warmth or coldness. 3000K appears warm, 4500K appears cold.
LED Light emitting Diode. A small low power solid state light source.
Lumen Quantity of light output
Ballast current control device needed to run fluorescent, CFL and discharge lamps. Built into the fitting, or in the case of most CFLs, ballast and lamp are in one lamp-replacement unit.
Cap the electrical connection end of a lamp.
BC Bayonet cap, push and twist connection
ES Edison screw cap
Efficacy output in lumens per watt. From a non-technical point of view can be considered as efficiency, although this is not strictly accurate.
Bipin 2 pin bulb base used on fluorescent tubes and some halogen lamps
Phosphor Coating inside fluorescent tubes that transforms UV into visible light
GLS general lighting service, the traditional filament light bulb.
Rough service lamp Shock and vibration resistant lamp
CFL Compact fluorescent lamp.
LV low voltage
Starter small device that works with a magnetic ballast to start the lamp. Used with fluorescent and some discharge lamps.
BL blacklight produces UV and violet light
BLB blacklight blue produces UV only. The blue glass filters out the violet.
Germicidal lamp produces short wavelength germicidal UV. Damaging to eyes, kills bacteria & erases eproms.
Uplighter Fitting sending most light upwards
Downlighter fitting sending most light downwards
Spotlight reflector lamp producing pool of light
Floodlight produces a wide spread of light nb some floodlights can look quite like spotlights
PAR aluminium reflector lamp, spotlight
Shelf fitting The normally fluorescent fitting is mounted on its side on a shelf so the lamp is concealed from view. The fitting however remains visible.
Trough Fitting The lamp is partially enclosed in a trough which conceals it from view. The fitting is also concealed.
Choke Magnetic ballast used in glowstart fluorescent fittings.
Halogen Type of filament lamp with better efficacy than traditional filament lamps. Contains bromine or iodine. Very high capsule temperature.
Sodium lamp Yellow lamps used for streetlighting
Mercury Discharge Lamp Icy white lamps used for streetlighting
SES small edison screw, a miniature lamp base
E14 a miniature screw fitting lamp base