A Treatise on Painting

by da Vinci Leonardo

The first things that disappear, by being removed to some distance, are the outlines or boundaries of objects. The second, as they remove farther, are the shadows which divide contiguous bodies. The third are the thickness of legs and feet; and so in succession the small parts are lost to the sight, till nothing remains but a confused mass, without any distinct parts.

Chap. CXXII.—Errors not so easily seen in small Objects as in large ones.

Supposing this small object to represent a man, or any other animal, although the parts, by being so much diminished or reduced, cannot be executed with the same exactness of proportion, nor finished with the same accuracy, as if on a larger scale, yet on that very account the faults will be less conspicuous. For example, if you look at a man at the distance of two hundred yards, and with all due attention mean to form a judgment, whether he be handsome or ugly, deformed or well made, you will find that, with all your endeavours, you can hardly venture to decide. The reason is, that the man diminishes so much by the distance, that it is impossible to distinguish the parts minutely. If you wish to know by demonstration the diminution of the above figure, hold your finger up before your eye at about nine inches distance, so that the top of your finger corresponds with the top of the head of the distant figure: you will perceive that your finger covers, not only its head, but part of its body; which is an evident proof of the apparent diminution of that object. Hence it often happens, that we are doubtful, and can scarcely, at some distance, distinguish the form of even a friend.

Chap. CXXIII.—Historical Subjects one above another on the same Wall to be avoided.

This custom, which has been generally adopted by painters, on the front and sides of chapels, is much to be condemned. They begin with an historical picture, its landscape and buildings, in one compartment. After which, they raise another compartment, and execute another history with other buildings upon another level; and from thence they proceed to a third and fourth, varying the point of sight, as if the beholder was going up steps, while, in fact, he must look at them all from below, which is very ill judged in those matters.

We know that the point of sight is the eye of the spectator; and if you ask, how is a series of subjects, such as the life of a saint, to be represented, in different compartments on the same wall? I answer, that you are to place the principal event in the largest compartment, and make the point of sight as high as the eye of the spectator. Begin that subject with large figures; and as you go up, lessen the objects, as well the figures, as buildings, varying the plans according to the effect of perspective; but never varying the point of sight: and so complete the series of subjects, till you come to a certain height, where terrestrial objects can be seen no more, except the tops of trees, or clouds and birds; or if you introduce figures, they must be aerial, such as angels, or saints in glory, or the like, if they suit the purpose of your history. If not, do not undertake this kind of painting, for your work will be faulty, and justly reprehensible[29].

Chap. CXXIV.—Why Objects in Painting can never detach, as natural Objects do.

Painters often despair of being able to imitate Nature, from observing, that their pictures have not the same relief, nor the same life, as natural objects have in a looking-glass, though they both appear upon a plain surface. They say, they have colours which surpass in brightness the quality of the lights, and in darkness the quality of the shades of the objects seen in the looking-glass; but attribute this circumstance to their own ignorance, and not to the true cause, because they do not know it. It is impossible that objects in painting should appear with the same relief as those in the looking-glass, unless we look at them with only one eye.

The reason is this. The two eyes A B looking at objects one behind another, as M and N, see them both; because M cannot entirely occupy the space of N, by reason that the base of the visual rays is so broad, that the second object is seen behind the first. But if one eye be shut, and you look with the other S, the body F will entirely cover the body R, because the visual rays beginning at one point, form a triangle, of which the body F is the base, and being prolonged, they form two diverging tangents at the two extremities of F, which cannot touch the body R behind it, therefore can never see it[30].