| In the context of art, the term "perspective" refers to an effect of three-dimensionality that is artificially produced or enhanced. The illusory third dimension is that of depth, which is to say the apparent distance between the viewer of an artwork and the various objects depicted within that artwork. Although perspective has been powerfully incorporated into the arts of sculpture and architecture, its most amazing deployment has been in the sphere of painting. This is because painting is essentially a two-dimensional form of art. Thus, the visual effect of perspective appears all the more marvelous when it proves capable of magically transforming a flat, two-dimensional canvas into what appears to be a three-dimensional spatial field. In De Pictura, a renaissance textbook on painterly techniques, Leon Alberti describes perspective paintings as so many glances through illusory windows out into an imaginary world. As Alberti explains, when the viewer is confronted with such paintings, he or she does not seem to be looking at a work of art; rather, the viewer seems to be looking into the work. The feeling that there is actually something "inside" of the painting, something situated at an actual distance from the viewer who stands in the work's foreground, is precisely the optical illusion that we have come to call "perspective." |
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But how exactly do painters manage to conjure forth this artificial dimension of depth and distance on the surface of their paintings? The earliest technique for rendering a realistic perspective was pioneered by ancient Greek sculptors, who created vivid, realistic scenes in bas relief. The technique they used is now called "foreshortening," and it involved depicting figures and objects in a diminished scale (i.e., making them smaller) to suggest that they are farther away from the viewer. At the same time, by depicting objects and figures in an enhanced scale (i.e., making them bigger), these objects and figures were made to appear closer to the viewer. The visual effect of a truly three-dimensional perspective arose when ancient artists learned to diminish and enhance the scale of various objects and figures in one and the same work of art. This made certain, larger objects in the sculpted scene appear to be closer to the viewer while other, smaller objects in the same scene appeared farther away. These works thus achieved an artificial element of depth--the illusory distance between foreground objects and background objects--that we now refer to as "perspective." And this ancient Greek technique of foreshortening objects to create a sense of perspective eventually resurfaced in the sphere of painting during the Renaissance, where it quickly led to the development of full-fledged perspectivism. |
Da Vinci's Last Supper, 1498
| While the ancient Greek technique of foreshortening contributed much towards creating the illusory third dimension of depth in painting, it was not until the early 1400's that "true perspective" in art would be mathematically understood and recreated with precision upon canvas. At this time, Italian Renaissance artists became concerned with the problem of rendering the dimensions of the visible world with absolute accuracy. These artists subsequently spearheaded the development of an artistic movement that we now call "perspectivism." To the ancient technique of foreshortening they added another important technical device, which they called "linear" or "mathematical" perspective. This device involved positing a point of greatest depth in the rendered scene of a painting. And this point, known as the "vanishing point," was very often a spot in the center of a horizon where either the land or sea joined with the sky. If the scene portrayed happened to be inside a house or building, then the vanishing point was very often situated in or beyond a window set in the background wall of the room. Furthermore, painters incorporating the device of linear perspective aligned the shapes and figural arrangements of their compositions in such a way as to suggest that every aspect of a given painting is organized in a linear relation to its vanishing point. In other words, everything included in the picture is situated along one of a series of traceable vectors, called "orthogonals," which stretch and converge towards the furthest removed point of the painting's background. Generally speaking, Renaissance artists favored using a single vanishing point to organize and orient the perspective of their paintings. This device is accordingly called "single-point perspective painting." Later artists would come to use two or more vanishing points in their works, thus developing the related devices of "two-point" and "multiple-point" perspective painting. In any case, by combining the technical devices of foreshortening and linear perspective, artists from the Renaissance period up to the present have been capable of recreating a realistic sense of three-dimensional space upon the flat surfaces of their canvases. |
