Chapter 34
OF DARK LEAVES IN FRONT OF TRANSPARENT ONES.
When the leaves are interposed between the light and the eye, then that which is nearest to the eye will be the darkest, and the most distant will be the lightest, not being seen against the atmosphere; and this is seen in the leaves which are away from the centre of the tree, that is towards the light.
[Footnote: See Pl. XXVIII, No. 2, the lower sketch.]
434.
OF THE LIGHTS ON DARK LEAVES.
The lights on such leaves which are darkest, will be most near to the colour of the atmosphere that is reflected in them. And the cause of this is that the light on the illuminated portion mingles with the dark hue to compose a blue colour; and this light is produced by the blueness of the atmosphere which is reflected in the smooth surface of these leaves and adds to the blue hue which this light usually produces when it falls on dark objects.
OF THE LIGHTS ON LEAVES OF A YELLOWISH GREEN.
But leaves of a green verging on yellow when they reflect the atmosphere do not produce a reflection verging on blue, inasmuch as every thing which appears in a mirror takes some colour from that mirror, hence the blue of the atmosphere being reflected in the yellow of the leaf appears green, because blue and yellow mixed together make a very fine green colour, therefore the l.u.s.tre of light leaves verging on yellow will be greenish yellow.
A cla.s.sification of trees according to their colours.
435.
The trees in a landscape are of various kinds of green, inasmuch as some verge towards blackness, as firs, pines, cypresses, laurels, box and the like. Some tend to yellow such as walnuts, and pears, vines and verdure. Some are both yellowish and dark as chesnuts, holm-oak. Some turn red in autumn as the service-tree, pomegranate, vine, and cherry; and some are whitish as the willow, olive, reeds and the like. Trees are of various forms...
The proportions of light and shade in trees (436-440).
436.
OF A GENERALLY DISTRIBUTED LIGHT AS LIGHTING UP TREES.
That part of the trees will be seen to lie in the least dark shadow which is farthest from the earth.
To prove it let a p be the tree, n b c the illuminated hemisphere [the sky], the under portion of the tree faces the earth p c, that is on the side o, and it faces a small part of the hemisphere at c d. But the highest part of the convexity a faces the greatest part of the hemisphere, that is b c. For this reason-and because it does not face the darkness of the earth-it is in fuller light. But if the tree has dense foliage, as the laurel, arbutus, box or holm oak, it will be different; because, although a does not face the earth, it faces the dark [green] of the leaves cut up by many shadows, and this darkness is reflected onto the under sides of the leaves immediately above. Thus these trees have their darkest shadows nearest to the
437.
OF THE SHADOWS OF VERDURE.
The shadows of verdure are always somewhat blue, and so is every shadow of every object; and they a.s.sume this hue more in proportion as they are remote from the eye, and less in proportion as they are nearer. The leaves which reflect the blue of the atmosphere always present themselves to the eye edgewise.
OF THE ILLUMINATED PART OF VERDURE AND OF MOUNTAINS.
The illuminated portion, at a great distance, will appear most nearly of its natural colour where the strongest light falls upon it.
438.
OF TREES THAT ARE LIGHTED BY THE SUN AND BY THE ATMOSPHERE.
In trees that are illuminated [both] by the sun and the atmosphere and that have leaves of a dark colour, one side will be illuminated by the atmosphere [only] and in consequence of this light will tend to blueness, while on the other side they will be illuminated by the atmosphere and the sun; and the side which the eye sees illuminated by the sun will reflect light.
439.
OF DEPICTING A FOREST SCENE.
The trees and plants which are most thickly branched with slender branches ought to have less dark shadow than those trees and plants which, having broader leaves, will cast more shadow.
440.
ON PAINTING.
In the position of the eye which sees that portion of a tree illuminated which turns towards the light, one tree will never be seen to be illuminated equally with the other. To prove this, let the eye be c which sees the two trees b d which are illuminated by the sun a; I say that this eye c will not see the light in the same proportion to the shade, in one tree as in the other. Because, the tree which is nearest to the sun will display so much the stronger shadow than the more distant one, in proportion as one tree is nearer to the rays of the sun that converge to the eye than the other; &c.
You see that the eye c sees nothing of the tree d but shadow, while the same eye c sees the tree b half in light and half in shade.
When a tree is seen from below, the eye sees the top of it as placed within the circle made by its boughs[23].
Remember, O Painter! that the variety of depth of shade in any one particular species of tree is in proportion to the rarity or density of their branches.
[Footnote: The two lower sketches on the left of Pl XXVIII, No. 3, refer to lines 21-23. The upper sketch has apparently been effaced by Leonardo himself.]
The distribution of light and shade with reference to the position of the spectator (441-443).
441.
The shadows of trees placed in a landscape do not display themselves in the same position in the trees on the right hand and those on the left; still more so if the sun is to the right or left. As is proved by the 4th which says: Opaque bodies placed between the light and the eye display themselves entirely in shadow; and by the 5th: The eye when placed between the opaque body and the light sees the opaque body entirely illuminated. And by the 6th: When the eye and the opaque body are placed between darkness and light, it will be seen half in shadow and half in light.
[Footnote: See the figure on the right hand side of Pl. XXVIII, No. 3. The first five lines of the text are written below the diagram and above it are the last eight lines of the text, given as No. 461.]
442.
OF THE HERBS OF THE FIELD.
Of the plants which take a shadow from the plants which spring among them, those which are on this side [in front] of the shadow have the stems lighted up on a background of shadow, and the plants on which the shadows fall have their stems dark on a light background; that is on the background beyond the shadow.
OF TREES WHICH ARE BETWEEN THE EYE AND THE LIGHT.
Of the trees which are between the eye and the light the part in front will be light; but this light will be broken by the ramifications of transparent leaves-being seen from the under side-and l.u.s.trous leaves-being seen from the upper side; and the background below and behind will be dark green, being in shadow from the front portion of the said tree. This occurs in trees placed above the eye.
443.
FROM WHENCE TO DEPICT A LANDSCAPE
Landscapes should be represented so that the trees may be half in light and half in shadow; but it is better to do them when the sun is covered with clouds, for then the trees are lighted by the general light of the sky, and the general darkness of the earth. And then they are darkest in certain parts in proportion as those parts are nearest to the middle of the tree and to the earth.
The effects of morning light (444-448).
444.
OF TREES TO THE SOUTH.
When the sun is in the east the trees to the South and to the North have almost as much light as shadow. But a greater share of light in proportion as they lie to the West and a greater share of shadow in proportion as they lie to the East.