Painting Trees: Universal Light and the Shadows of Foliage
Paint landscapes under a veiled sun; why dense-leaved trees darken toward the centre
This page of the Treatise on Painting continues Leonardo's rules for rendering trees and foliage. He advises depicting landscapes when the sun is veiled by cloud, so that the fields receive a diffuse universal light and not the particular light of the sun, which would make sharp cut shadows very different from the highlights. He explains that dense-leaved trees such as laurel, box and holm oak carry their darkest shadows nearest the centre of the crown, and that the highlights of dark leaves take on the blue of the sky reflected in their polished surfaces.
On this page
Paint landscapes under a veiled sun for even light
The true practical method for depicting the countryside with its plants is to choose a moment when the sun is covered in the sky, so that the fields receive a universal light rather than the particular light of the sun. Direct sunlight makes sharply cut shadows that differ greatly from the highlights.
Dense-leaved trees darken toward the middle of the crown
A tree thick with leaves, like the laurel, box or holm oak, does not see the darkness of the ground but sees the darkness of its own leaves divided by many shadows. This darkness reverberates upward onto the undersides of the leaves above, so that such trees have shadows the darker the nearer they lie to the centre of the tree.
Highlights of dark leaves reflect the blue of the air
The highlights of darker leaves partake more of the colour of the air mirrored in them. The bright of the lit part composed with the dark makes a blue within itself, and this brightness arises from the blue of the air reflected in the polished leaf surface, augmenting the blue that brightness tends to generate against dark things.