DRAWING ELLIPSES

Nothing gives away an artist’s deficiencies more quickly than a drawing with poorly constructed ellipses; even to the untrained eye, lack of accuracy in drawn ellipses can usually be spotted, although the viewer may not quite understand what is wrong with the picture or how to fix the problem.

ELLIPSES: FORESHORTENED CIRCLES

An ellipse is a circle in perspective. It sounds simple, yet many artists find it challenging to accurately draw them. Once you learn some simple rules and properties of ellipses, the mysteries will be revealed, and you can successfully and easily render them.

We see ellipses in objects all around us—rims of cups, bowls, and other cylindrical objects; wheels on cars, bicycles, and roller skates, etc. Observed straight on, these forms are circular, but it is much more common to see them at angles. Therefore, it is in the artist’s best interest to learn as much as possible about ellipses.

In this still life, notice the gradual change in length of the blue minor axes of the ellipses as they rise toward eye level. The relative width of the major axes (red) stays the same, however.

One of the most important elements that dictates how we see the shape of an ellipse is its relationship to eye level. Knowledge of eye level and its location is a key component in almost every drawing, but especially in regard to ellipses.

ATTRIBUTES OF ELLIPSES

All circles fit into a square. When drawing an ellipse, first visualize a circle within a square and then project it into perspective to observe the foreshortening that occurs. The circle is divided into equal quadrants by a horizontal axis and vertical axis. Notice what happens when the square and circle are projected into perspective space: The horizontal axis shortens in width, and the vertical axis shortens in height.

On this bottle, the horizontal axis is the major axis of the ellipse (red line). The vertical axis is the major axis of the bottle, but it is the minor axis of the ellipse (blue line). These axes are always at right angles to each other when a symmetrical object stands up straight on the ground plane. The major axis, or midline, of the bottle coincides with the ellipse’s minor axis and is perpendicular to the ellipse’s major axis. This is the rule when any symmetrical object’s base rests on the ground plane.

Demonstrated are a few illustrations of the wrong ways to draw ellipses. The first example shows the classic “football” shape of an incorrectly drawn ellipse; the edges of an ellipse should always be rounded and never pointed. In the second example, the edges of the ellipse are too rounded, with the top and bottom edges too straight across their length. Ellipses should always curve continuously and have no straight edges. In the third example, the ratio of closed-to-open ellipses is wrong. The nearer the ellipse is to the viewer’s eye level, the tighter that ellipse appears; conversely, the farther from eye level, the more rounded the ellipse appears.

Wrong Ways to Draw Ellipses

SIZE RATIO OF ELLIPSES

Ellipses can be explained in degrees of angle to the viewer’s eye level, with 90 degrees equal to a true circle and 0 degrees when the ellipse is viewed at eye level. As an ellipse moves toward eye level, the length of the minor (vertical) axis is reduced. As an ellipse moves away from eye level, the length of the minor axis increases. Ellipses that are parallel to each other, or in similar locations horizontally, will have very similar size ratios (see next image).

ELLIPSES NOT PARALLEL TO THE GROUND PLANE

As a circular object moves away from standing vertically on the ground plane, there are similarities and differences to the ellipses that we have already discussed.

This photograph illustrates how ellipses relatively close to each other across a horizontal location are similar in their ratio of roundness. For instance, all of the ellipses at the objects’ bases (magenta) have similar ratios of roundness; let’s say 50 degrees. The middle, tan-colored ellipses are all around 30 to 35 degrees, and the very tops of the objects (purple) are about 10 to 15 degrees, as they are the closest to eye level.

Study this photograph of four pots resting horizontally on the ground. Notice that the pot farthest from the viewer has an ellipse for its rim that is almost a straight line; as the pots rotate around the ground plane toward the viewer, the ellipse of the rim rounds out more with each successive rotation toward the viewer.

Also note that the pots tend to shift away from eye level and farther down on the picture plane. The center midline axes of the pots also present more of a perspective angle to the viewer. These midline axes are directly related to the perspective angle of the side of each pot, bisecting its symmetry.

As the pots rotate toward the viewer from left to right, the ellipses become rounder, the blue midline (minor axis) becomes more of an acute angle to the picture plane, and the red major axis always stays at a right angle to the minor axis. The angle of the major axis of the pot (the minor axis of the ellipse) is dictated by the perspective construction angles of the sides of the pot.

Here is what the sketch of these pots would look like, with the major axis of the pot (also the minor axis of the ellipse) and the major axis of the ellipse sketched in lightly.