Lumenlaadun

Lumenlaadun is a term used in the lighting industry to describe the overall perceived quality of light produced by a source, in addition to its brightness as measured by luminous flux (lumens). It is not an official technical standard, but a practical concept that designers and researchers use to balance the quantity of light with its qualitative characteristics as experienced by people in a space.

The concept encompasses several interrelated factors. These include color rendering and color quality (how accurately colors appear under the light), color temperature, and the spectral power distribution of the source. It also covers perceptual aspects such as flicker, glare, contrast, and spatial distribution or uniformity. Beyond vision, lumenlaadun can consider comfort and usability in specific contexts, such as circadian-friendly lighting or task-specific illumination.

Measurement of lumenlaadun is not governed by a single universal metric. Instead, it relies on a combination of metrics and assessments. Established measures like color rendering index (CRI) and newer approaches such as TM-30 provide information about color fidelity and color quality. Luminance and illuminance distributions, flicker metrics, and an evaluation of glare are also relevant. Standards bodies such as the CIE and IEC provide guidance on photometric and colorimetric properties, while industry practices vary by application.

Applications of the concept occur across architectural lighting, retail or showroom design, office environments, horticulture, automotive lighting, and street or public lighting. The goal is to achieve a balance between adequate brightness and a light quality that supports visual comfort, accurate color perception, and appropriate ambiance.

See also: lumen, luminous flux, color rendering index, TM-30, SPD, color temperature, glare.