Have you ever left the house feeling confident about your appearance, only to realize in different lighting that you look completely different? This is because the color rendering index (CRI) of a light source can have a significant impact on how colors appear. In this article, we’ll explain what CRI is, why it’s important, and which types of lights have the best CRI.
What Is Color Rendering Index (CRI)?
CRI is a metric that measures how accurately a light source displays color. It is measured on a scale of 1 to 100 and is calculated by comparing the chromaticities of a test light source to a reference illuminant of the same correlated color temperature. The smaller the difference in chromaticities, the higher the CRI. CRI is tested using 8 standard color swatches, and the predefined color samples used to calculate CRI are often called “Ra,” or rendering average.
Why Is CRI Important When Selecting LED Lighting?
CRI is an important consideration when selecting LED lighting because it can significantly impact how colors appear. LEDs with high CRI ratings will render colors accurately, making textures, fine details, and colors stand out. This has a flattering effect on people, making their hair and skin look rich and healthy. High CRI LEDs are valuable in both the home and workplace, as they can make fruit and vegetables look juicier and more appetizing or allow doctors to do their jobs safely. Conversely, LEDs with low CRI ratings will make things appear drab and dull, causing people to look unappealing and their skin to look lifeless.
What Is The Good Number of CRI?
As a general rule of thumb, you should aim for a minimum CRI of 80. However, the closer to 100, the better. CRI scores in the 90s are exceptional, showing colors almost as accurately as daylight, and any slight discrepancies will not be noticeable to the human eye. A CRI of 90 or higher is recommended for hospitals, museums, print studios, and retail shops. Scores of 80 are also acceptable and may be useful in places that require softer or more ambient lighting. As CRI drops below 70, color inaccuracies become more evident to the human eye.
Incandescent vs LED vs Fluorescent: Which Has Better CRI?
In the past, CRI was seen as relatively unimportant when choosing a light source because traditional incandescent bulbs were popular. Incandescent bulbs have a perfect CRI score of 100, but they have gradually been phased out in most countries due to their poor energy efficiency. Fluorescent bulbs may seem like an attractive alternative to incandescent bulbs because of the lack of heat they give off, but the CRI of a fluorescent varies from bulb to bulb and can be anywhere from 50 to 85. The same is true of LEDs, which in the past were known to have poor CRIs. However, as technology has evolved, most LEDs now have an average CRI of 90.
CRI is an essential consideration when lighting your home or property, and the CRI calculation is used universally by the lighting industry. However, it isn’t without limitations. Back in 2015, the Illumination Engineering Society produced a replacement for the CRI that uses 99 color samples. So is color rendering about to get even more complex? Only time will tell. As for now, aim for a minimum CRI of 80 and choose high CRI LEDs to make colors appear accurately and people look their best.