Glossary

Ambient lighting

General lighting or overall illumination in a room. Ambient lighting radiates an even and comfortable level of brightness, without glare, to allow visibility and easy movement in the room. Natural light from the sun and moon and a central light source usually provide enough ambient lighting and form a good base for a lighting plan. Additional lighting is provided by table lamps, wall lights and floor lamps.

Accent lighting

Used to draw the eye to specific points in a room, such as sculptures or paintings. Is usually provided by recessed lighting, track lighting or picture lights.

Cathode

An electrode or terminal from which a current leaves a polarized electrical device.

Ceiling rose

Typically round, a ceiling rose is a decorative mount affixed to the ceiling from which a flexible lead for an electric light passes.

Chandelier

An ornamental, and often ornate, hanging light with branches and holders for several candles or bulbs; from the French candelabrum, which, literally, means something that holds candles.

Compact fluorescent lamp (CFL)

Uses electricity to excite mercury gas until it emits ultraviolet light. That light is then passed through a phosphor, which causes it to emit more visible light. CFLs are often called energy-saving bulbs and are more environmentally friendly than incandescent bulbs because they last longer and use less energy for the same level of light intensity.

Desk lamp

A type of table lamp that sits on a work desk or can be clamped onto the edge of a desk. Desk lamps are a form of task lighting. They provide sufficient illumination for detailed work and, if positioned well (by directing light away from eyes and screens), reduce glare around computer screens and prevent eye strain.

Floor lamp

A tall lamp, usually with a base, that stands on the floor.

Fluorescent

A glass tube coated on the inside with phosphor that radiates a bright light when mercury vapour in the tube is acted upon by a stream of electrons from the cathode.

Flush mount

A light that is fixed butted up to the ceiling with no gap in-between; often used in rooms with low ceilings. The Cross Ceiling Light is an example of this.

LED

Stands for a light-emitting diode; an LED is a semiconductor device that emits visible light when an electric current passes through it. The light is not particularly bright; it is often monochromatic – occurring at a single wavelength. LED light bulbs are a more environmentally friendly alternative to incandescent bulbs.

Lumens

The amount of light emitted from a bulb (more lumens = more light); 100-watt bulb gives out about 1600 lumens.

Luminance

This is the light we see; the light reflected off surfaces.

Monochromatic

Light with only one wavelength or colour present.

Pendant light

A single light fixture that hangs from the ceiling and is usually suspended by a flexible cord, chain or metal rod; usually mounted to the ceiling with a canopy. Chandeliers are a type of pendant lighting.

Photometry

The measurement of light and its related quantities.

recessed_02Recessed down lights

A highly versatile form of lighting, recessed down lights are installed into the hollow of a ceiling. They are unobtrusive, with adjustable, eyeball-style fittings that allow you to direct light in a particular direction.

Sconce

A light fixture affixed to the wall in such a way that it uses the wall for support; the light is usually directed upwards.

Semi-flush mount

A light that is fixed to the ceiling with a stem or a part that provides a bridge between the light and the ceiling. The Sirius Pendant is an example of this kind of lighting.

Suspended lighting

A light fixture that hangs from the ceiling by a cord, chain or metal rod. An example of this is the Bella Metallic Pendant Light.

Table lamp

A small or large lamp designed to stand on a table.

Task lighting

Provides enough brightness in one area to perform specific jobs such as reading or working. Good task lighting provides enough light without glare, shadows or eye strain. Table lamps and floor lamps are the usual sources for task lighting.

Uplighter

A lamp or wall light positioned to throw light upwards. Often used in landscape gardening to highlight trees or statues.

Wall light

A lamp that is fixed onto a wall.

Wall washers

Mounted on walls or recessed into ceilings, wall washers give out an even stream of light. They can be used to make a small room look bigger (if you have a white or light-coloured ceiling).

Watt

Named after Scottish engineer James Watt (1736–1819), a watt is a unit of power in the International System of Units and is defined as a joule per second (the rate at which electrical energy is dissipated).