CRI (Color Rendering Index)

CRI stands for Color Rendering Index. CRI is an important criterion of the visual performance of a light source. CRI measures the ability to reflect colors of electrical light sources according to natural light sources which mean sunlight. In short, in lighting devices, CRI expresses how the objects are closed to their true colors.

In detail; CRI is a measure of the ability to show colors that close to its true or natural color according to a reference source known as incandescent or sunlight.

CRI value expressed with a numerical value between 0-100. If CRI value close to 100, it shows the colors well. 100 represent the maximum CRI value.

Sunlight represents perfect light and CRI value accepted as 100.

If CRI value is greater than 80, it is acceptable for most of the applications. However, CRI value 90 and above lights are needed in areas where colors are more important.

If we mention about CRI values of common lights; incandescent and halogen lamps 100, metal halide lamps 85, fluorescent lamps 70, high-pressure sodium vapor lamp 25. Most LED light sources have over 70 and 80 CRI value. It should be remembered that these values can be different according to the manufacturer’s products or products of different characteristics of the same manufacturer.

Lightings with high CRI value used in art galleries, retail stores, food sections in markets, textile sector, hairdressers and, health facilities. As in the examples, lighting with high CRI value is needed indoors.

Using high CRI value lights makes the colors more clear, vivid color and, distinguishable in illuminated areas.

Spectroradiometer is used to measure the CRI value. The measurement device with a spectral sensor is directed to the light source and it can be easily measured by this way. There are cost saving, hand-held, mobile devices to measure the color rendering index of light sources. It is possible to measure quickly and evaluate the special light sources used in several areas by these devices.