A beam of light is reflected diffusely, that is, its ray is scattered in all directions, if it strikes a rough or matte surface

A beam of light is reflected when a light ray strikes a mirror like, shiny or glossy surface at an angle where the angle of incidence is reflected as a light beam with equal angle of reflection

It is the passage of light through a medium when light falls upon a transparent material

A false ceiling of diffusing material with light sources mounted above

A directional lighting to emphasize a space or an object

A device to control the amount of light by reducing the voltage or the current

A device which changes either amount or color or both of light passing through it.

A fixture producing concentrated direct lighting from a single bulb. It may be recessed in or mounted on the ceiling

A recessed or semi-recessed lighting unit with a rotating spherical element that may be turned to project light in any direction

A term often applied to a can-type of recessed incandescent downlight

Electromagnetic radiation within a certain portion of the electromagnetic spectrum.

A device used to measure an electromagnetic spectrum

The deliberate use of light to achieve a practical or aesthetic effect.

It is a solid angle at the center of a sphere subtending an area on the surface equal to the square of the radius of the sphere

An international commission developing definitions, standards, and procedures for the art, science, and technology of lighting

The light originating from the sources facing each other, as from windows in opposite walls

The light originating from the sources not facing each other, as from windows in opposite walls

It is an open area or vertical shaft in the center of a building, typically roofed with glass

A large open air or skylight covered space surrounded by a building

Utilized openings in the building to bring sunlight from the roof into deeper levels of the building

A horizontal surface that reflects daylight deep into the building

Dining (casual) recommended illumination level

Reading (ordinary) recommended illumination level

Drafting (moderaate) recommended illumination level

Sewing (difficult) recommended illumination level

Surgery (severe) recommended illumination level

Also called ambient lighting. Lighting designed to provide a uniform level of illumination throughout an area.

Lighting designed to provide a relatively high level of illumination over a small area with surrounding area of lower intensity from spill light

Lighting designed to provide a strong illumination for visually demanding activity, such as drafting or reading

Lighting that calls attention to a particular object or feature in the visual field, or that forms decorative pattern on a surface

Diffuse light that produces little contrast and poorly defined shadows on the subject

To emphasize by illustrating with a strong light

Direct light that produces high contrast and distinct shadows on the subject

Lighting unit consisting of one or more electric lamps with all the necessary parts and wiring

Light source having a maximum dimension less than one fifth the distance form the source to the surface illuminated

Light source having a significant dimensions in two directions such as a large window or a luminous ceiling

Light source having one dimension significantly greater than its other dimension such as a fluorescent lamp