The Third Dimension

An essay on depth by Pam Coulter Blehert

"How does the artist do that?" we exclaim, seeing the vast panorama of a landscape or the modeling that gives depth to the face of the portrait or the still life on a two- dimensional painting.

A kind of magic sets the painter apart from the non-artist. Of course the painter has many tools, but one of them is a knowledge of some of the rules and conventions for conveying the illusion of depth.

Whether you are artist or viewer, a knowledge of how this illusion is achieved may help you understand what you see in a painting.

Most people have at least a passing familiarity with "linear perspective" even if they don't remember how it works. Perspective is the use of certain geometrical devices to create the illusion of depth on the flat picture plane. For example, two lines approaching each other (the two sides of a road) may indicate two parallel lines moving away from the viewer.

Simple one-point perspective assumes that there is a horizon line and that the "vanishing point" is located at a point on that horizon, sometimes directly in front of the viewer, much as if you were standing on a highway in east Montana.

you can play with that viewpoint by assuming the viewer is either above the horizon (a giant's view) or below (ant's eye view). Two-point perspective guides us in rendering objects which have two visible sides (rows of houses or interiors, for example).

Linear perspective is the best known means of signaling depth, but, although particularly handy for interior design and architectural drawing, is only one of many interesting means to explore depth on the flat plane. All the other means of signaling depth used by a painter, when lumped together, are sometimes referred to as aerial perspective.

You might say that in painting, there are three basic concerns: value, color, and composition. Each of these areas has certain attributes that can either enhance or destroy the feeling of depth in a painting.

Value deals with variables in light and darkness. (Most people are somewhat familiar with the "grey scale.") Value can also be used as an organizing factor to create the illusion of depth.

Color, our second concern, also has value. The word value actually comes from a root meaning "strength." Yellow, for instance, has a much lighter value, or strength, than blue. In addition, color has hue and saturation. These attributes can be used to give the illusion of depth.

The many and varied theories of composition through the ages basically boil down to the artist's notions about how well something "hangs together." There are many compositional means that additionally contribute to the illusion of depth. We can actually approach the various means for showing depth by considering them as subdivisions under the categories of value, color, and composition.

USE OF VALUE TO ACHIEVE DEPTH

Value can be used as a dimensional tool by assigning dark and light areas to spatial planes (going from very dark to very light as we move into the distance or vice versa.) An easy way for me to communicate this to you is to tell you how the Smokey Mountains looked from Skyline Drive on a recent trip when we stopped at an overlook in late afternoon. The trees nearest us, as we looked over this vista, were dark. Successive ranges got lighter and lighter until I could barely distinguish one range from another or the most distant range from the sky.

Value can also be used by arbitrarily assigning bands of light and dark moving back across the picture plane. This method probably wouldn't stand alone as an abstract device, but it works well in pen and ink drawings or etchings, when we have sufficient understanding of what we are seeing. For instance, in late afternoon, who has not seen a row of trees casting long shadows across a road? The bands of light and dark divide the picture plane into foreground, middle ground, and background.

DEFINING DEPTH WITH COLOR

Color has three qualities that can be used to render depth: value, hue, and saturation. Add color, even a monochromatic color, to the foregoing discussion about value, and you have color value as an organizing tool.

Hue is the name of a color. It is that attribute by which we distinguish red from blue. The primary hues are red, yellow and blue. If we arrange all the hues in a "color wheel" -- the three primary colors at three equidistant points -- and then "bleed" from color to color around the wheel (red leading to orange and then yellow, etc.) we find that one side of that wheel is "warmer" and the other is "cooler". (One side is also inherently darker, and this is also an important consideration when using color.)

In depth perception, our human vision reads warm colors (red, orange, yellow, yellow-green) as closer to us and cool colors (blue, purple blue-green) as more distant. Notice that, if you stand looking out over distant fields, while you may still see a red roof in the distance, in general, farther objects will be "bluer" and nearer objects, brighter and warmer.

The third attribute of color that is important is saturation. Saturation is, practically speaking, how much of a given pure color is crammed into a given space. The easiest example I can give is watercolor. If you take a tube of watercolor and squirt some onto a dish, then load a brush with the full color with no water added you generally have a fully saturated color.This is only false when white has been added to the tube, as in cerulean blue. But if you begin adding water to the tube color before you apply it to the paper, you get a less and less saturated color. More saturated color reads to our mind as closer than less saturated color.

Another facet of saturation is neutrality. Take another look at the color wheel. Each primary color has a secondary color opposite it. If you mix the two, you get a "muddy color" -- the neutral components between the two colors. If this muddy color contains more of the warm than the cool color, your neutral will be more brown than grey; if more cool than warm, then more grey than brown. Theoretically, if our color wheel were perfect, an equal mix of two complementaries would result in black. And, interestingly enough, warm neutrals, such as brown "read" as closer to the viewer than "grey".

COMPOSITIONAL DEPTH CLUES

The third category is really a sort of catch-all. I identify it as compositional elements of depth for want of a better title. It includes all the structural ways that we "read" depth in a two-dimensional plane: size, detail, modeling, overlap, position on the picture plane and direction.

Size is a primary (and very obvious) depth indicator. In a representational composition, things that are larger read as closer, provided this fits with our world concept. (Obviously, you can have anomalies, such as a large elephant much farther away than a small mouse, but there are generally other indicators that then supply the depth clues.)

Detail relates to our normal means of seeing. We "focus" on things that are close. In life, they are frequently also things that are more significant to us {our friends, our stuff, our food.) They can also be more menacing, if threatening (our enemies, if seen up close, may take on a preternatural nicety of detail.) The camera frequently imitates this tendency, with its "depth of focus." We get thrown off, in painting, if the artist translates near and far as equally detailed and clear. We expect the distance to blur. This may relate to time as well as distance, and also to importance or emphasis.

Modeling is not so much a depth indicator as a volume indicator, but it relates to depth. If we have a curved or rounded plane, the shape of a face or an apple) it pulls the two-dimensional surface out of its flatness. Modeling actually uses other depth factors to accomplish its ends. For instance, roundness can be conveyed by moving from light to dark, or from full saturation to grayed color, or from warm to cool.

Overlap is a depth clue that is so obvious that it is often missed in discussions. Everybody knows that if something is nearer, it will block out something that is further away. This is an important element for the artist who wishes to convincingly incorporate depth. Notice that many landscape painters, to give more depth to their paintings, will incorporate some very near element, maybe a branch or tree trunk, something which identifies where we are in relation to the whole scheme.

Position on the picture plane is also important. Things that are closer to you frequently seem lower. You can actually play with the dimensionality of a painting. Place a still life low when you paint it, so that you look over and around the forms, and you have stretched the space. Place it high, so that all items stand on one narrow horizon, and you have abstracted the shapes to their fine outlines, denying depth.

Position in landscapes is equally of interest and, in addition, may have a spiritual overtone. We may like being high up, master of all we survey. Or, we may like the sense of being big. On the other hand, like the Japanese landscape painter, we may like the sense of being but a mote in a vast and grandiose land.

Direction relates to classic perspective. I mention it here because it can be used in a more casual fashion. By direction, I mean the way diagonal lines or elements in the composition seem to lead the eye around the picture plane. You may have flat fields of wheat and grain leading up the canvas - representing a landscape. Tilt the boundaries of those fields ever so slightly, and you have led the eye up and up and up. We tend to follow the boundaries of forms linearly. So our eye moves up and, as it were, into the canvas.

USE AND MISUSE OF DIMENSION

People get fascinated when depth is done well in a painting. There is something magical about that illusion of the third dimension. But there's another point that needs remarking on.

Art is an evolution. It breaks rules. Each of these guidelines can be used, singly or in combination, to throw off our usual ways of relating to the world, thus creating, in some, 'dis'-ease, in others, the excitement of discovery.

For instance, a large and well defined form low on the canvas but neutral in color (or pale) gives us conflicting information. A green-yellow sky (warm and close) opposed to a dark purple field (as in one of Van Gogh's paintings of a peasant sowing) disturbs our normal information channels. It becomes exciting because we can't just accept it. We have to examine it. Something isn't quite right. It is, in fact, this very element that makes abstract or surreal painting so interesting to some and disturbing to others.

Use of color or form with more attention to their associative effects without regard to (or in defiance of) their natural placement still subconsciously triggers our tendency to relate back to known depth clues. So the purely abstract artist like Kandinsky (whose canvases may seem to some to be a sophisticated emulation of the scribblings of 3 year olds) still has to contend with depth. Matisse, Picasso, even Jackson Pollack (as well as the realists) can be viewed with these points in mind.

A more comprehensive look at the various schools of art and how they use or neglect depth clues is beyond the scope of this article. What I hope to have done here, however, is to give you an idea of some of the tools that the artist has in his magic hat. You too can use them!

The above article was published in The Reston Review, 4th Quarter, 1992. Copyright ©1992,1999 by Pam Coulter Blehert. All Rights Reserved. Use for teaching is OK. Please cite source. Any examples or hyperlinks demonstrating the above points would be gratefully received by the author.