Color Rendering (CRI)

A lamp's ability to represent colors in objects is called its Color Rendering Index or CRI. The higher the CRI, the more vibrant or closer to natural the colors appear. The scale of 0 to 100 is based on a relative measurement which rates light sources. Lamps that have CRI ratings of 70-80 are considered good, while those lamps, which have a CRI of 80 or above are considered excellent and are also considered to have a high quality of light. The higher the CRI, the better perceptions of appeal objects and people have.

Efficacy / Lumens Per Watt (LPW)

Simply put, the light output of a lamp is measured in Lumens. The higher the lumen rating of a particular lamp, the brighter the lamp's light output will be. A lamp's efficacy is the relationship of which a lamp is able to convert power (Watts) into light (Lumens) as expressed in lumens per watt (LPW). LPW can be best compared to "miles per gallon." The more efficiently a car engine operates, it increases the mileage obtained for each gallon of gasoline. The same efficiency rules apply here. The more efficiently the conversion of power (Watts) is into usable light (Lumens), the higher the efficacy of the lamp.