Värintoistoarvo

Värintoistoarvo, often abbreviated as CRI from the English "Color Rendering Index," is a quantitative measure of a light source's ability to reproduce the colors of various objects faithfully compared to a natural light source, such as sunlight. It is a crucial characteristic, particularly in applications where accurate color perception is important.

The CRI scale ranges from 0 to 100. A CRI of 100 indicates that the light source renders colors identically to the reference source under specific test conditions. Lower CRI values suggest that the light source alters the colors of objects, making them appear different from how they would look under natural light.

To determine the CRI, a light source is compared to a reference illuminant (which is typically sunlight or a blackbody radiator that approximates sunlight at a given color temperature) by observing how it renders a set of eight standard color samples. These samples are chosen to represent a range of hues and saturation levels. The differences in appearance between the test light source and the reference illuminant are then quantified.

A higher CRI value is generally desirable for applications like art galleries, retail displays, and photography studios, where accurate color representation is paramount. In residential and general lighting, while still important, the necessity for extremely high CRI may be less critical, though increasingly, manufacturers are aiming for higher CRI values across their product lines. The quality of color rendering can significantly impact the perceived ambiance and realism of a space.