CRI stands for Color Rendition Index and is the quantitative measurement used to determine the color of a lamp’s light. The higher the CRI, the more true to sunlight the light is and the better sight you will have when trying to see details. Different CRI can be used in different settings for different reasons. Here is a few of those:
For most indoor home lighting should provide a softer, warmer light typically around 3200 to 4500 Kelvin. This provides good lighting levels while also not being so bright to wash out the surrounding area. If reading or an indoor office setting, brighter lights, on the spectrum of 5000 Kelvin to 6500 Kelvin is typically used to mimic sunlight in an office setting, especially those with no available sunlight from windows or sky lights.
For outdoor lighting, staying closer to sunlight, from 4500 Kelvin up to 6500 Kelvin, for nighttime lighting provides best sight. Bright white lighting at night outside can provide the ability to see your keys if you drop them to more details of objects in the distance. This is important for safety and security of areas around homes and businesses.
There are instances, such as coastal and wildlife friendly areas that would require a much lower CRI due to the long wavelengths of the light. The longer wavelength still allows humans to see, but animals typically do not notice these lights.
Different Lighting Colors for Different Tasks
A study on the Effects of LED Color Temperature on Office Workers shows that people prefer a warmer light indoors when dealing with relaxing activities; however, a higher CRI when dealing with task specific activities such as reading or office work. Participants in these studies have indicated that they are less fatigued in brighter whiter lighted areas then with warmer light, but also felt more eye fatigue.
Overall, the lighting CRI in the different areas can affect your productivity and visibility. Choosing the appropriate light color can impact how you see as well as your energy levels. What is the CRI of the light that you like best?