Unified Glare Rating (UGR)

A metric quantifying the discomfort glare from lighting installations, with lower values indicating less glare.

Glare

Visual discomfort or impairment caused by excessive brightness or contrast within the visual field.

Beam Angle

The angle at which light is emitted from a source, affecting the spread and intensity of illumination.

Candela (cd)

The SI unit of luminous intensity, representing the power emitted by a light source in a particular direction.

Luminance

The intensity of light emitted or reflected from a surface in a given direction, measured in candelas per square meter (cd/m²).

Illuminance

The amount of light falling onto a surface, measured in lux (lumens per square meter).

Luminous Flux

The total amount of visible light emitted by a source, measured in lumens.

Efficacy

The efficiency of a light source, expressed as lumens per watt (lm/W). Higher efficacy indicates better energy efficiency, reducing power consumption for the same light output.

Lumens

A measure of the total quantity of visible light emitted by a source.