Color rendering is the ability of a light source to produce color in objects. The CRI is expressed on a scale from 0-100, where 100 is the best in producing vibrant color in objects. Relatively speaki [..]

A measure of the color of a light source relative to a black body at a particular temperature expressed in degrees Kelvin (°K). Incandescent lights have a low color temperature (approximately 2800°K) [..]

Efficacy is an industry term for the amount of light produced per watt of electricity (comparable to efficiency). It is the rate at which a light bulb is able to convert electrical power (watts) into [..]

The unit of measure for the density of light as it reaches a surface. One footcandle is equal to one lumen per square foot. Measured footcandles are sensitive to the distance from the source to the su [..]

The density of luminous flux on a surface, is measured in footcandles (one lumen per square foot) or lux (one lumen per square meter).

The result of the use of light.

The energy that allows us to see. Light can be expressed in terms of intensity (candela), flux (lumen), luminance (candela/square foot), and exitance (lumen/square foot).

The unit of measure for the light energy which flows in air. The total light output from electric sources is expressed in lumens. A uniform source of one candlepower placed in a sphere emits 12.57 lum [..]

This term is used to describe the specific light which comes off the surface whether off a filament, light bulb, lens, louver, tabletop, etc. Luminance varies with both the direction at which you view [..]