What is CRI in LED lighting

CRI is a very commonly confused topic in the LED lighting industry.  By definition, CRI stands for Color Rendering Index and is measure the ability of a light source to accurately render all frequencies of its color spectrum when compared to a perfect reference light of a similar type (color temperature).

For us non-scientists, this translates into, “lights with a higher CRI level more accurately represent true color of an object.”

It is not widely known, but older technologies of lighting have higher CRIs than LED products do.  Tungsten/Halogen has the highest, followed by certain types of incandescent bulbs. However, many people think that they like the “light” produced from a LED better.  

What is important is to know how high of CRI you actually need.  CRIs above 80 are considered very good levels. Anything above 90 CRI is considered excellent and would only be necessary in very fine tasks requiring precise color discrimination such as certain types of printing.

CRI is often confused with kelvin color in the LED world.  Kelvin color is the color temperature the bulb gives off. It is often described as warm white (2700 Kelvin), cool white (4000 kelvin), or daylight (5000+ kelvin).  The kelvin color will also affect CRI levels.

LED fixtures and bulbs can be offered in a variety of kelvin colors, as well.  Not all LEDs give off the harsh blue color (high kelvin color) look. This is often what early generation LED products were sold with, and many people develop a bad feeling about the look and feel of LED lighting.  It is true that LED products can come in a very warm kelvin color to mimic the look of an incandescent bulb.