What Is Aerial Perspective? How Painters Create Depth with Colour

Aerial perspective (or atmospheric perspective) is a way of creating depth in a picture with colour rather than with lines. What lies far away is painted paler, bluer, lower in contrast and with less detail, because the air between the eye and the object scatters the light. Leonardo da Vinci described the principle and used it in the landscape behind the Mona Lisa, but it is also found in Chinese landscape painting and in Bruegel.

Facts

What the eye sees

Anyone who has stood on a height on a clear day and looked out over a landscape of ridges has seen aerial perspective. The nearest ridge is dark green and sharp, the next is blue-green, and the farthest are pale blue and almost transparent against the sky. The farther away the forms lie, the simpler they become and the softer their edges.

The explanation is that air is not completely transparent. It contains water vapour, dust and molecules that scatter light, and blue light is scattered most. That is why the sky is blue, and why a blue haze settles between us and everything far away. The more air, the more haze. Three things change at once: the value becomes lighter, the hue shifts towards blue, and the contrast between light and dark diminishes.

Two kinds of perspective

Renaissance painters had two tools for creating depth. Linear perspective builds space with lines: parallel lines running into the picture meet at a vanishing point, and objects grow smaller with distance. It works best for floors, streets and buildings with straight edges.

Aerial perspective builds space with colour and works best where there are no straight lines, in landscapes with mountains, forest and water. The two complement each other, and most painters have used both. The explanatory illustrations in the section on perspective in Looking at Art show them separately; aerial perspective also appears further down this page, where you can drag the haze and distance.

Leonardo and the Mona Lisa

Leonardo da Vinci wrote about aerial perspective in the notes on painting that were collected into a treatise after his death. He observed that objects lose their colour and outlines with distance and that the farthest mountains turn blue, and he urged painters to paint distant things paler and hazier in proportion to the distance.

The landscape behind the Mona Lisa is an exercise in exactly this. In the far distance, cliffs and water rise in blue-green, almost dissolved haze, while the woman in the foreground is painted in warm, dark tones. The contrast makes her seem to sit close to us, in front of a vast space. The same soft transitions are found in his sfumato, in which the contours dissolve as if in smoke. Read more in the guide to the Mona Lisa.

Bruegel and landscape painting

Pieter Bruegel the Elder painted Hunters in the Snow in 1565. Three hunters with dogs come down a hill in the foreground, dark against the snow. Below, a valley spreads out with frozen ponds and small figures skating, and in the far distance grey-green, pointed mountains rise against a pale green sky. The picture has almost no straight lines leading in; the depth comes from the colours growing cooler and weaker.

In the 17th century a simple scheme became common in landscape painting: brown in the foreground, green in the middle ground and blue in the distance. Claude Lorrain built his idyllic landscapes with a golden haze that dissolves the horizon, and J.M.W. Turner took it to the point where the whole picture can consist of light and air. Romanticism's Wanderer above the Sea of Fog also lives on layers of mist. See the landscape theme in the app.

China: mountains in mist

Aerial perspective is not a European invention. In Chinese landscape painting, mist and empty spaces separate the different layers of mountains so that they seem to lie at different distances. Fan Kuan's Travellers among Mountains and Streams, from about the year 1000, has an enormous mountain rising behind a band of mist, so that it seems both near and infinitely far away.

The painter Guo Xi described in the 11th century three ways of seeing distance in a landscape: the high, when one looks up towards a peak, the deep, when one looks in behind mountains, and the level, when one looks out across lowland towards the horizon. The mist and the thinner ink used for the distant serve the same purpose as Leonardo's blue haze. Read more about the period in the Song dynasty.

Seeing aerial perspective for yourself

Look at the background of a landscape painting and ask how the painter shows distance. Do the colours become paler and bluer? Do the edges become softer? Are there layers of haze or mist between foreground and background? Then compare it with a picture in which depth is built with lines, such as a street or a floor.

A simple test is to view the picture in greyscale, or to squint. The hues disappear and only the values remain, and it becomes clear how the distant areas lie in a paler, flatter tone. The term is also in the glossary, and the guide to how to read a painting shows more ways of looking.

How to recognise it

Exercise

How are distant mountains usually painted in aerial perspective?