midlightness

Midlightness is a concept used in color science and image processing to refer to brightness values that lie midway between the darkest and brightest parts of a scene or image. It is generally considered a descriptor for midtones, the tonal range that preserves detail in both highlights and shadows when dynamic range is limited.

Midlightness is not a formal measurement with a universally adopted scale, but it is often discussed in relation to established color metrics such as lightness in the CIELAB color space or luminance in linear RGB. On a typical 0–100 lightness scale, midlightness corresponds approximately to L* ≈ 50; on a 0–1 scale, about 0.5.

In photography and digital editing, midlightness is a target region for tone-mapping, histogram adjustments, and gamma correction to keep midtones readable while protecting shadows and highlights. In palettes and design, midlightness governs the perceived neutrality of greys and muted colors.

Perception and limitations: Human vision is more sensitive to midtones than extreme blacks or whites, so midlightness values often carry the most scene information. However, because midlightness is not standardized, its exact meaning can vary between workflows and devices, making consistent communication important.

See also: Lightness, L*, Luminance, Midtone, Tonal range, Exposure.