LuminanceLightness

Luminance and lightness are two distinct concepts in color theory and perception, often used interchangeably but with distinct meanings. Luminance refers to the amount of light emitted, reflected, or transmitted by an object or surface. It is a physical property measured in candelas per square meter (cd/m²) and is a key factor in how bright an object appears to the human eye. Luminance is influenced by the object's color, surface texture, and the light source illuminating it.

Lightness, on the other hand, is a perceptual attribute that describes how light or dark an object appears to the human eye. It is a subjective measure that takes into account the object's color, the surrounding environment, and the viewer's adaptation to the lighting conditions. Lightness is often represented on a scale from 0 (black) to 100 (white), with intermediate values corresponding to varying shades of gray.

The relationship between luminance and lightness is complex and influenced by several factors. For instance, two objects with the same luminance may appear to have different lightness if they are viewed under different lighting conditions or if they have different colors. Conversely, two objects with the same lightness may have different luminance if they are viewed under different lighting conditions or if they have different colors.

In summary, luminance is a physical property that measures the amount of light emitted, reflected, or transmitted by an object, while lightness is a perceptual attribute that describes how light or dark an object appears to the human eye. Understanding the distinction between these two concepts is crucial in fields such as color science, graphic design, and photography, where accurate color perception and reproduction are essential.