Aerial Perspective
Distant subjects appear lighter, less saturated, and less distinct as atmosphere creates visible spatial depth.
Aerial perspective, also called atmospheric perspective or color perspective, describes the way air alters the appearance of distant objects. As distance increases, contrast between an object and its surroundings weakens, internal detail becomes less distinct, and colors lose saturation while shifting toward the color of the intervening atmosphere, often blue but sometimes red or orange at sunrise or sunset. The term is associated with Leonardo da Vinci, although comparable effects appeared much earlier in painting. In photography, it names both a natural optical phenomenon and a compositional means of suggesting depth and recession in space.
The effect is especially visible in landscapes, mountain views, broad valleys, and cityscapes with fog, smoke, or moisture in the air. Such scenes often form a sequence of receding planes, with backgrounds growing progressively paler and softer. Early photographic materials, including calotype, waxed paper, and wet collodion processes, were strongly sensitive to blue light, so they often exaggerated haze and made middle and distant planes appear lighter than they seemed to the eye. Photographers could either emphasize or moderate this effect: soft focus and differential focus heightened the atmospheric dissolution of form, while combination printing or later filtering helped control haze, sky detail, and tonal balance.
The term is distinct from aerial viewpoint, which refers to a camera position above the ground rather than to atmospheric optical effects. It also differs from linear perspective: linear perspective organizes depth through converging lines and changes of scale, while aerial perspective does so through tonal gradation, reduced saturation, and diminishing clarity.