Luminance (Candela, cd/m2)

Luminance, measured in candelas per square meter (cd/m²), describes how bright a surface appears when viewed by the eye. Unlike illuminance, which is the amount of light falling onto a surface, luminance takes into account how much light is reflected or emitted from that surface in the viewer’s direction. Because it is directly linked to human visual perception, luminance is a critical measure for assessing glare, contrast, and overall visual comfort in lighting design.

Think: How bright a surface looks