Leonardo da Vinci, or the glory of painting
"LIMBS which are not in exercise must be drawn without showing the play of muscles. And if you do otherwise, you will have imitated a sack of nuts rather than a human figure.'
This is one of the notes on painting found in the second of the recently discovered Madrid Manuscripts of Leonardo da Vinci, dating from the first years of the sixteenth century.
All the elements of Leonardo's painting are present in the theories expressed in this manuscript. Another series of notes, in addition to those on form and colour, deals with light and shadow and the smooth transition from light to shadow, which is the true essence of the famous Leonardo sfumato.
When in the first period of his activity Leonardo was dealing with the problem of light and shadow he conceived of objects in terms of geometrical entities and was mainly concerned with the study of the gradations and degrees of intensity of the shadows.
After 1500 his main concern becomes the study of light and shadow on objects placed in the open air, thus taking into account colour and reflections. Light becomes the vehicle that blends the elements of landscape into a harmony of transitions from colour to colour, and this Leonardo calls "grace'.
The human figure, too, becomes part of the landscape (one thinks of the Mona Lisa, The Virgin and St. Anne, Leda) and thus participates in the phenomena of reflection, refraction and interplay of coloured shadows, as is the case with every other object placed under the light of the sky. What can be seen under the projection of a roof is also to be seen under the chin of a human face.
One of Leonardo's most beautiful observations pertains to the way a human face should be represented. He advises the painter to arrange the setting so as to achieve the most delicate sfumato effects in the shadows, what he calls "the gracefulness of shadows, smoothly deprived of every sharp contour'.
The setting is provided by the walls of the houses flanking the street, through which the light penetrates--light made of air without brightness, a golden, diffuse light such as that of Giorgione.
Now, says Leonardo, "light ends upon the pavement of the street and rebounds with reflected motion at the shadowy parts of the faces, brightening them considerably. …