Valonlaatu

Valonlaatu is a Finnish term that translates to "quality of light." It describes the characteristics of light in a given environment, including color, brightness, diffusion, uniformity, and color rendering. The term is used across lighting design, photography, film, and studies of human perception.

Derived from valon (of light) and laatu (quality), valonlaatu in Finnish technical discourse discusses how light affects color fidelity, visibility, and mood. It contrasts with light quantity (valon määrä) and efficiency, focusing on perceptual attributes rather than power.

Measured in practice through color rendering metrics such as CRI and TM-30, correlated color temperature (CCT), spectral power distribution, glare, and diffusion. Practical assessment combines instrument readings with subjective evaluation to determine how a lighting setup will be perceived.

In architecture and interior design, valonlaatu guides luminaire selection to achieve a desired atmosphere; in photography and cinema, it influences color rendition and mood; in urban planning, it helps shape safe and comfortable night-time environments. Human-centric lighting aims to align valonlaatu with human perception and well-being.

See also: Lighting design; Color temperature; Color rendering.