CRIwaarde

CRIwaarde refers to the Color Rendering Index value, the Dutch term for a numerical measure of how accurately a light source renders colors compared with a reference illuminant. It is widely used in lighting design, product labeling, and procurement to gauge color fidelity.

The CRI is determined by comparing the appearance of standardized color samples under the tested light to their appearance under a reference light of the same correlated color temperature. The index runs from 0 to 100, with higher values indicating more faithful color rendering. The commonly cited Ra value is the average of the first eight test color samples (R1 through R8). Additional indices, such as R9 (which targets strong red tones) and R10 through R15, assess rendering in other specific color areas and are reported by some lamps.

Interpretation of the CRIwaarde depends on application. Values above 80 are typically considered acceptable for most indoor tasks, while values above 90 are often preferred in contexts requiring precise color discrimination, such as art galleries, photography, or medical environments. A higher CRIwaarde generally implies more natural color appearance under the light.

Limitations of the CRI include dependence on the chosen reference illuminant, insensitivity to certain aspects of color saturation, and potential misrepresentation of colors under certain spectral power distributions. Consequently, two light sources with similar CRIwaarden can render colors differently in practice. Modern lighting evaluations sometimes supplement CRI with newer metrics like TM-30-15, which offer a more comprehensive assessment of color fidelity and gamut.

In practice, the CRIwaarde guides product labeling and selection, with many LED products reporting Ra and, in some cases, R9. It remains a common though imperfect standard in lighting specifications.