The stereoscope

by David Brewster

Fig. 47.

The same observations apply to a portrait of the human face. In looking at a human profile let us suppose the breadth of the nose to be one inch, that of the ear one inch, and that we view this profile at the distance of three feet from the ear, which is two inches nearer the observer than the nose. The apparent magnitude of the ear and nose will be as thirty-eight to thirty-six inches, whereas if we view the profile from the distance of one foot the ratio will be as fourteen to twelve, that is, the ear will be increased in apparent size more than the nose. Hence it follows that all pictures should be viewed under the same angle of apparent magnitude under which they were seen by the artist as taken photographically, for if we view them at a greater or less angle than this we do not see the same picture as when we looked at the original landscape or portrait, under the same angle of apparent magnitude.

From the observations made in the [preceding Chapter] on photographic and stereoscopic portraiture, the reader must have already drawn the inference that the same landscape or building, seen at different distances, varies essentially in its character,—beauties disclosing themselves and defects disappearing as we approach or recede from them. The picture in the camera, therefore, as used by Mr. Thomson, or, what is still better, with the exception of colour, the photograph obtained by the same instrument, will supply the artist with all the general materials for his picture. The photograph will differ considerably from any sketch which the artist may have himself made, owing to certain optical illusions to which his eye is subject. The hills and other vertical lines in the distance will be lower in the photograph than in his sketch.[59] The vertical lines of buildings will converge upwards in the photograph, as they ought to do, in receding from the eye; and in the same picture there will be a confusion, as we shall afterwards shew, in the delineation of near and minute objects in the foreground, increasing with the size of the lens which he has employed.

In his admirable chapter “On Finish,” Mr. Ruskin has established, beyond a doubt, the most important principle in the art of painting. “The finishing of nature,” he states, “consists not in the smoothing of surface, but the filling of space, and the multiplication of life and thought;” and hence he draws the conclusion, that “finishing means, in art, simply telling more truth.” Titian, Tintoret, Bellini, and Veronese have, as he has shewn, wrought upon this principle, delineating vein by vein in the leaf of the vine, petal by petal in the borage-blossoms, the very snail-shells on the ground, the stripe of black bark in the birch-tree, and the clusters of the ivy-leaved toad-flax in the rents of their walls; and we have seen that a modern artist, Delaroche, considers a finish of inconceivable minuteness as neither disturbing the repose of the masses, nor interfering with the general effect in a picture.

The Pre-Raphaelites, therefore, may appeal to high authority for the cardinal doctrine of their creed; and whatever be their errors in judgment or in taste, they have inaugurated a revolution which will release art from its fetters, and give it a freer and a nobler aim. Nature is too grand in her minuteness, and too beautiful in her humility, to be overlooked in the poetry of art. If her tenderest and most delicate forms are worthy of admiration, she will demand from the artist his highest powers of design. If the living organizations of the teeming earth, upon which we hourly tread, are matchless in structure, and fascinating in colour, the palette of the painter must surrender to them its choicest tints. In the foreground of the highest art, the snail-shell may inoffensively creep from beneath the withered leaf or the living blade; the harebell and the violet may claim a place in the sylvan dell; the moss may display its tiny frond, the gnarled oak or the twisted pine may demand the recognition of the botanist, while the castle wall rises in grandeur behind them, and the gigantic cliffs or the lofty mountain range terminate the scene.

If these views are sound, the man of taste will no longer endure slovenliness in art. He will demand truth as well as beauty in the landscape; and that painter may change his profession who cannot impress geology upon his rocks, and botany upon his plants and trees, or who refuses to display, upon his summer or his autumn tablet, the green crop as well as the growing and the gathered harvest. Thus enlarged in its powers and elevated in its purposes, the art of painting will be invested with a new character, demanding from its votaries higher skill and more extended knowledge. In former times, the minute and accurate delineation of nature was a task almost impossible, requiring an amount of toil which could hardly be repaid even when slightly performed; but science has now furnished art with the most perfect means of arresting, in their most delicate forms, every object, however minute, that can enter into the composition of a picture. These means are the arts of photography and stereoscopic re-combination, when rightly directed, and it is the object of the present chapter to shew how the artist may best avail himself of their valuable and indispensable aid.

Every country and district, and even different parts of the same district, have a Flora and Geology peculiar to themselves; and the artist who undertakes to represent its beauties owes to truth the same obligations as the botanist who is to describe its plants, or the mineralogist its rocks and stones. The critic could not, in former times, expect more details from his unaided pencil than it has generally furnished; but with the means now at his command, he must collect, like the naturalist, all the materials for his subject. After the camera has given him the great features of his landscape, he must appeal to it for accurate delineations of its minuter parts,—the trunks, and stems, and leafage of his trees—the dipping strata of its sandstone beds—the contortions of its kneaded gneiss, or the ruder features of its trap and its granite. For the most important of these details he will find the camera, as at present constructed, of little service. It is fitted only to copy surfaces; and therefore, when directed to solid bodies, such as living beings, statues, &c., it gives false and hideous representations of them, as I have shewn in a [preceding chapter]. It is peculiarly defective when applied to parts of bodies at different distances from it, and of a less diameter than the lens. The photograph of a cube taken by a lens of a greater diameter, will display five of its sides in a position, when its true perspective representation is simply a single square of its surface. When applied to trees, and shrubs, and flowers, its pictures are still more unsatisfactory. Every stem and leaf smaller than the lens, though absolutely opaque, is transparent, and leaves and stems behind and beyond are seen like ghosts through the photographic image.

Fig. 48.