färgindex

Färgindex, often abbreviated as CRI (Color Rendering Index), is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully compared to a natural light source, such as sunlight. It is a crucial parameter when evaluating the quality of artificial lighting, 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. Lower CRI values suggest a less accurate color reproduction. The index is determined by comparing the spectral power distribution of the light source to that of a reference illuminant, which is typically a blackbody radiator that matches the correlated color temperature of the source being tested.

The evaluation involves observing the appearance of eight standard pastel-colored test samples under the light source and comparing them to their appearance under the reference illuminant. The average difference in color appearance is used to calculate the CRI. Higher CRI values are generally desirable for applications like retail environments, art galleries, museums, and photography studios, where accurate color representation is paramount. Conversely, for general illumination purposes where color fidelity is less critical, lower CRI values may be acceptable. Understanding Färgindex helps in selecting appropriate lighting solutions for specific needs.