Common Terms

  • COLORING RENDERING INDEX (CRI) – represents the quality of light and its faithfulness to render colors correctly, that is to enable us to perceive colors as we know them. The ideal CRI is 100, and some incandescent bulbs approach this level. LEDs and CFLs use different design components in trying to equal the CRI of incandescent bulbs. LED bulbs CRI ratings range from 70 to 95, and the best CFLs have ratings in the mid 80s.
  • LUMINOUS FLUX – the flow of light measured in lumens. Much of an incandescent light is wasted because it’s emitted in every direction. LED on the other hand puts out directional light, sending all of the light exactly where it’s needed.

  • LUMEN– a unit of standard measurement used to describe the amount of light contained in an area as perceived by the human eye. The more lumens, the brighter the light.
  • KELVIN– a unit of measurement on the color temperature of the light. It defines the amount of pure white, yellow, red and blue in a light. It is measured in degrees Kelvin, denoted by a ‘K’ behind a number, e.g. 3000K

Colour Temperature/kelvin Chart

1900k Candle light or sunlight at sunrise or sunset
2000k-2700k Often used as ascent lighting to blend in with fluorescent 2700k applications
3000k-3200k Used as a primary light source for retail applications
3700k Coasted lamps, where a “softer” metal halide light source is desired
4000k General lighting; factories; parking lots, warehouse
5000k-5500k Daylight lamps: horticulture, aquariums, hight color definition
5600k Nominal sunlight (mid day during summer)
6000k Start to get a blue tint like some actomotive headlights