In yesterday’s opening article, I demonstrated how artists from the Renaissance to the start of the nineteenth century used aerial perspective to add depth to landscape views. This is the combination of at least five related optical effects:

• a reduction in the difference in lightness between an object and its background,
• resulting in a reduction in the range of lightness values, or contrast,
• resultant loss of detail in objects,
• reduction in chroma generally,
• a shift in hue, normally towards blue (‘cooler colours’).

The early nineteenth century saw a succession of exponents of aerial perspective.

Richard Parkes Bonington’s Fishmarket near Boulogne from 1824 is one of his most significant early paintings, and probably one of the best of his brief career.

This detail view shows how loosely he handled many of the figures and objects, and the exaggerated aerial perspective which gives the work such depth. You can see here a background which has, relative to the foreground:

• less lightness in the highlights;
• a narrower range of lightness;
• loss of detail;
• reduction in chroma;
• a shift in hue towards cooler (bluer) colours.

Caspar David Friedrich’s painting of The Watzmann (1824-5) has its aerial perspective enhanced by the snowline. In the foreground are rock runs and barren land, with patchy low grass, behind which are tottering rock pinnacles bearing a few trees. The middle distance contains rolling forest, behind which the land rises abruptly in a rock cliff, and a rock hill showing intensely folded strata. In the far distance are a pair of sharp peaks, snow burying their crevices and chimneys, and covering the tops. Here the colours and form of the terrain reinforce its aerial perspective.

Another precocious landscape artist, Alexandre Calame’s superb Swiss Landscape was painted in about 1830, when the artist was about twenty. It shows the shore of one of the country’s large lakes, probably Lake Geneva, and is a textbook example of aerial perspective.

When Camille Corot spent his formative years sketching in oils in the Roman Campagna, he used aerial perspective extensively. This later view of Avignon from the West, painted in 1836, is a fine example of its use to give the impression of vast space and distance.

The French Impressionists, who grew from Corot’s plein air painting, initially employed classical aerial perspective. Claude Monet’s view of The Thames below Westminster from 1871 is a radical departure in some respects, but he exaggerates its aerial perspective with mist.

Within a few years, Impressionist landscapes were starting to abandon such conventions. In Alfred Sisley’s Willows on the Banks of the Orvanne from 1883, he actually reverses the optical effects, and gets away with it. An irregular row of pollarded willows, with well-developed heads, crosses the foreground, behind which there is the river Orvanne, reeds, and a tall stand of poplars. Behind this dense grill is a fence, field, and distant buildings, at the midpoint of the painting.

If anything, the foreground has cooler colours than the vegetation on the far bank, and the palings of the distant fence increase contrast in the middle distance. Despite this, the painting maintains its planes and doesn’t dissolve into confusion.

Of the Impressionists, it’s often claimed that it was Paul Cézanne who flouted previous conventions on perspective the most, as a mark of his ‘primitivism’ and rebellion against the academy.

The evidence for this isn’t consistent with the claims. In a great many of Cézanne’s landscapes throughout his career, he followed many of the perspective conventions, including the use of aerial perspective, as shown in this view of Montagne Sainte-Victoire, where the distant mountain is different in warmth and/or hue to the middle- and foreground. Above is an example from 1886-87, and below a version painted by his close friend Auguste Renoir in 1888-89.

Late in his career, though, Cézanne did paint some views in which he abandons aerial perspective completely.

His Le Lac d’Annecy is generally taken as the inception of his most radical style and approach to painting. Compared to modern satellite images, the distance between the artist’s point of view and the Château de Duingt on the opposite side of the lake is 800 metres (just under half a mile), but it appears to be far closer than that, at least in part because he uses not one of the techniques for showing aerial perspective.

By comparison, Vincent van Gogh was far more conventional in his use of aerial perspective. This early sketch of Wheat Field with Cypresses made in the summer of 1889 follows each of the five principles listed at the start of this article. Unlike many Post-Impressionists, van Gogh appears to have remained closer to the plein air tradition, and this painting may even have been completed in a single sitting in front of the motif.

Camille Pissarro also appears to have been largely conventional in his use of aerial perspective, as shown so well in his late series of Paris, such as his Boulevard Montmartre, Spring Morning from 1897. This lends depth to the street, and complements his careful perspective projection.

By the early twentieth century, several successful artists had adopted styles which incorporated varying degrees of the ‘primitive’, including the abandonment of aerial perspective. The Norwegian Nikolai Astrup, who was influenced by Rousseau, painted landscapes with an assumed naïvety, understating or omitting aerial perspective, and incorporating multiple perspective projections into the same image, as in his Farmstead in Jølster (1902).

Two women, sheltering from the rain under black umbrellas, are walking up a muddy path which threads its way through the wooden farm buildings, guiding a young girl with them. Astrup delights in the colourful patches which make up each of the turf roofs, and the contrasting puddles on the grass.

Although a sophisticated and technically accomplished oil painting, aerial perspective is minimised, with small differences in the five properties listed at the start. This makes the hills look less distant and more impending, which probably reflects what the artist felt living in the narrow fertile strip on the edge of the fjord.

For nearly five hundred years, painters had developed and followed the conventions of aerial perspective, to enhance the impression of depth given by their two-dimensional representations of the three-dimensional world. With the advent of photography, some artists controlled or even eliminated aerial perspective altogether to achieve novel effects.