Thursday, September 8, 2016

Why you need high "CRI"

Okay - so you're probably wondering, "What is CRI and why do I need it?"

Color rendition refers to how colors appear when viewed under a particular light source. Daylight is the perfect light source and gives the best color rendition.  We tend to compare how things look based on what we're accustomed to seeing in daylight.  

The higher the CRI, the better the color rendering ability. Light sources with a CRI of 85 to 90 are considered good at color rendering. Light sources with a CRI of 90 or higher are excellent at color rendering and should be used for tasks requiring the most accurate color discrimination.

The International Commission on Illumination (CIE), the global authority on lighting and color, has even devised a Color Rendering Index (CRI) that uses a scale of 1-100 to measure how well a light source reproduces color in the same way sunlight does. The closer a source gets to 100, the more accurately it renders colors.

Superior color rendition is important so colors and textures look their best.  It is recommended that for homes, the CRI be 80 or better.  My personal choice is 90 or better.  Although you may be using LED bulbs that are 2700K, it still looks too white.  K which stands for Kelvin is the color temperature of a light source and 2700 is the color temperature of incandescent lighting, however, the average CRI of incandescent is 98. 

This is why when viewing a red apple indoors under an incandescent bulb, for example, the apple’s color will appear very similar to how it looks outside in daylight. Under a white fluorescent bulb with a 50-60 CRI, it will have a bluish cast.

Unfortunately, the bulbs you find in big box and hardware stores do not indicate the CRI.  Most likely it's 80 at best.  If you want the optimum color rendition, look for stores and on-line sources that specialize in bulbs.