What technique uses objects of different sizes to create the illusion of depth?

linear perspective, a system of creating an illusion of depth on a flat surface. All parallel lines (orthogonals) in a painting or drawing using this system converge in a single vanishing point on the composition’s horizon line.

Linear perspective is thought to have been devised about 1415 by Italian Renaissance architect Filippo Brunelleschi and later documented by architect and writer Leon Battista Alberti in 1435 (Della Pittura). Linear perspective was likely evident to artists and architects in the ancient Greek and Roman periods, but no records exist from that time, and the practice was thus lost until the 15th century.

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The three components essential to the linear perspective system are orthogonals (parallel lines), the horizon line, and a vanishing point. So as to appear farther from the viewer, objects in the compositions are rendered increasingly smaller as they near the vanishing point. Early examples of Brunelleschi’s system can be seen in Donatello’s relief St. George Killing the Dragon (c. 1416–17) and Masaccio’s painting The Holy Trinity (1425–27), a dramatic illusionistic crucifixion. Andrea Mantegna (who also mastered the technique of foreshortening), Leonardo da Vinci, and German artist Albrecht Dürer are considered some of the early masters of linear perspective. As the limitations of linear perspective became apparent, artists invented additional devices (e.g., foreshortening and anamorphosis) to achieve the most-convincing illusion of space and distance.

As a landscape painter, I aim to make my pictures look real. This means conjuring up an illusion of depth that gives viewers the feeling they could stroll right into the scene. Without this bit of magic, the picture looks flat and uninviting.

Two Types of Perspective

When we go for a walk, we have the benefit of seeing the world with stereoscopic vision. Our two eyes allow us to see what’s closer and what’s farther away, which helps us to navigate without bumping our shins. On the other hand, the viewer of a painting is, in a sense, visually handicapped. Because the surface of a painting is flat, looking at it is like seeing the scene with only one eye. In order to help the viewer, I like to “push” the illusion of depth.

This is where perspective comes in; it’s vital to creating the illusion of depth. There are basically two kinds of perspective: linear and aerial. Linear perspective is the type we most often think of. Its lexicon includes vanishing points; one-, two-, and three-point perspective and horizon lines. An Italian engineer and architect, Filippo Brunelleschi, laid out this geometric system for drawing buildings in 1413, during the Renaissance.

The second kind of perspective, aerial (or atmospheric), has to do with how the air between us and an object affects our perception of the object’s color, especially with regard to value, temperature, and chroma. Unlike linear perspective, which is an artificial system used to create the illusion of space, aerial perspective is a product of natural laws. It was first used in the Netherlands during the 15th century. Leonardo da Vinci, among others, observed and catalogued the effects and theorized why the effects occurred.

Prior to the Renaissance, many European paintings looked flat and two-dimensional. As observations grew more acute and mathematics more precise, both aerial and linear perspective helped artists achieve a high level of realism, epitomized in Flemish still life and landscape paintings of the 17th century.

Linear Perspective Clues

The techniques of perspective can be boiled down to a few simple tricks. But they’re not tricks, really; they’re important visual clues, all based on close observation from life. Every day we see and visually interpret these clues, but we’re so used to them that we don’t notice — unless we’ve developed a keen eye while in the habit of working directly from life.

As artists, we need to recognize that these visual clues can be valuable tools in making a successful painting. Let’s first take a look at what tools linear perspective offers us.

Overlapping objects

Overlapping objects tell us what’s in front of what (I classify this with linear perspective because it has to do with the positioning of shapes). It’s a simple concept. We learned as toddlers that if one thing obscures another, that means the thing obscured is farther away. It’s surprising how often this concept is forgotten by beginning painters. You should overlap shapes as much as possible to make the spatial relationships clear.

Scale

The scale, or apparent size of an object, diminishes with distance. We’ve all seen a row of telephone poles and noticed that the ones farther off seem to be smaller. You don’t need telephone poles to make the illusion work in a painting. Just include a few objects that are familiar to the viewer and of similar actual size (as opposed to apparent size) so that the diminution makes sense. Including figures is one way of showing scale.

Aerial Perspective Clues

Now let’s look at aerial perspective. Air scatters sky light, and any dust or moisture suspended in the air increases the scattering. This scattering is responsible for most of the atmospheric effects we see, and the more air between the viewer and an object, the more pronounced the effects are.

The next two clues deal with the way atmosphere affects value.

Contrast

Contrast decreases with distance. Some of the scattered sky light spills into dark areas or may even be bounced back to the viewer, making the dark areas seem lighter. Light areas are also affected, but the effect isn’t as apparent.

Sharpness of Edges

The sharpness of edges also decreases with distance. An edge is defined as a value contrast between two adjacent shapes, and the sharper the contrast, the sharper the edge. Because contrast decreases with distance, the edges, being dependent on contrast, seem to become softer.

The next two aerial perspective clues deal with color. Scattered sky light is a low-chroma blue, and that sky light affects the color of objects
it falls upon.

Temperature

The temperature of a color decreases with distance. The scattered blue sky light shifts colors to the cooler end of the spectrum. Colors don’t necessarily become blue, however. Red, for example, becomes a dull red-violet, then a dull violet. Yellow becomes a dull yellow-green.

Chroma

The chroma (richness) of a color decreases with distance. The scattered blue sky light isn’t a high-chroma blue; instead, the blue is mixed with white light (other colors), thus lowering its chroma. This “impure” light is what decreases the saturation of all colors in the landscape. At infinity, one can expect the color to become completely desaturated.

Additional Clues

There are two more ways to create depth that I find helpful. Detail (as well as texture) diminishes with distance. For example, in a grassy field, the foreground grasses may show individual stalks and leaves. As you look farther out, the individual stalks merge into larger masses.

In landscapes especially, a road, stream or fence line that runs from the foreground into the distance provides an easy path for the eye. Although this approach can be heavy-handed, a subtle eye path can be an effective clue to receding distance.

Space in a Nutshell

In short, to create the illusion of depth and space, make sure you keep your warm and rich colors, dark accents, textural marks, and detail in the foreground. Save your cool and dull colors, softer edges, and low-contrast elements for the middle ground and distance. In addition, use overlapping and scaled elements to suggest distance. Finally, if you can find a path for the eye, include it. You can see how I implement many of these clues in the demo below.

Even when I don’t see all of these clues in the scene before me, I include or exaggerate their effects so visual depth is clearly conveyed. Doing so keeps my viewer from getting “lost in space.”

Demo: Give the Viewer Some Space!

The following demonstration shows how aerial perspective, texture, and a path for the eye can be used to enhance the sense and illusion of depth in a landscape.

Materials:

• Surface: Canson Mi-Teintes pastel paper in steel gray
• Pastels: Prismacolor NuPastel, Faber-Catell Polychromos, Rembrandt, Mount Vision, Girault, Sennelier
• Fixative: Lascaux spray

1. Block In

It’s very easy to block in a painting with just a few simple colors and then use aerial perspective to create the illusion of depth. In this first stage, I’ve blocked in with a dark, warm green for the trees; a lighter, warm green for the grassy area; and a mid-value blue for sky and water. This block-in has a flat appearance, almost like a poster. The only clues to distance come from linear perspective elements: the path for the eye created by the stream and the diminishing apparent size of trees in the distance.

2. Set Value Range

My values were generally correct, but the sky and water were too flat. I lightened the lower sky with a creamy, light yellow tint. This value dictated how light I could make the distant line of trees. I similarly lightened the far end of the water, where it reflects the lower sky. I darkened the near water, where it reflects the unseen overhead sky, with dark purple. This dictated how dark (and saturated) I could make the grasses.

3. Adjust Tree Values

I scumbled over the farthest trees with lighter, cooler greens, and also some blues. As I worked my way to the closer trees, I used darker and warmer greens. I also introduced a very dark note into the shadowed side of the closest tree so it would have more contrast between light and dark. After my initial pass in these areas, I went back in with blues and greens to fine-tune the effect until I was satisfied with the illusion of depth and distance.

4. Adjust Grass Values

The grasses needed a similar treatment. I worked a light red-violet over the most distant grasses to both gray down and cool the greens. As I moved from background to foreground, I started with cooler blue-greens and gradually warmed up the colors, ending with oranges, reds, and yellow- greens. In the distance I kept my marks small and soft, but in the foreground I made them larger and sharper- edged to make the grasses seem close to the viewer.

5. Final Touches

I continued fine-tuning the temperatures, chromas, values, textures, and edges, resulting in a convincing illusion of distance in Barrier Beach Grasses.

Michael Chesley Johnson is a frequent contributor to Artist’s Magazine. Johnson teaches plein air workshops throughout the United States. Visit his website at mchesleyjohnson.com.