Understanding Color Rendering Index
Color Rendering Index (CRI) is the system that the lighting industry uses to measure how a light source shows the color spectrum (quality of the light). CRI is rated on a scale from 0 to 100. The higher the number the “Truer” colors look of object being illuminated. Incandescent light bulbs (including halogen) and daylight (the sun) are rated as a 100. The below image is a rendering of how CRI can affect the color of the object a light bulb is illuminating.
The reason that some light sources are better (higher CRI) at showing color has to do with the light spectrum that it produces. An object can only reflect the light spectrum that is present. So if there is very little red in the light source spectrum, then the apple will look less red. The more of the visible light spectrum a light source emits, the truer the reflected color from anything being illuminated. Below are some examples of light source spectrums.
(The LED and fluorescent spectrums can vary from brand to brand but these will give you a good idea.)
While the incandescent does not have the same levels of the daylight spectrum, it does have the entire visible color spectrum that daylight produces, making it similar to daylight. As a rule of thumb, lights with a CRI of 80 or more work for most situations but people with a critical eye and in some retail applications higher CRI lights may be preferred. In many retail applications the store wants the items being illuminated to look as true to the actual color as possible (Clothing Stores, Car Dealers, etc.).
Each technology has its pluses and minuses depending on the use. For example LED lights produce little to no UV or Infrared light which is the part of the spectrum that fades colors. That, along with the energy savings give LEDs the added benefit of being great for lighting artwork and clothes. Halogens have the ability to produce lots of light output (brightness) for illuminating large areas but use more energy than LEDs. There are trade offs for any of the lighting technologies. So in many cases you may need to experiment with different types until you find what you like. Below is a video that will explain CRI. Please remember we are here to help, so give us a call if you have any questions 866-499-0947.
Video that will explain CRI