Everyone knows that things appear smaller at a distance, but most people don't have a good feel for how dramatically the perceived size falls off as things move away. Try this simple experiment to convince yourself. Hold a pencil straight out in front of you, point up. Lock your elbow so that your hand is a reproducible distance away from your eyes. Use the pencil as a measuring stick to something in your field of view - an object on a shelf, a person's head. Shut one eye and put the tip of the pencil at the visual tip of the object. Now mark the bottom of the object with your thumb. Hold your thumb in the marked place on your pencil and move a few feet further away from the object.

Now hold up your pencil again. Remember - lock your elbow so your hand is the same distance from your eyes. Sight the object again. Did you expect to find it had shrunk in perceived size as much as it did? This experiment usually surprises people. They expect to find the measured distance smaller, but not THAT much smaller. (And now you know why artists are stereotyped as squinting at things with a pencil held out at arm's length.) It is the shrinking with distance phenomenon that creates 'perspective'. It's a bane to many artists and artist-wannabes, but it doesn't have to be. The problem is, most people know too much about the true shape of things to be able to turn a three-dimensional scene into a two-dimensional projection of the scene. They know, for instance, that a road is the same width throughout, so although they try to take distance into account, they don't 'shrink' the road enough.

The first sketch is how a naive or young artist might draw a road running away from the viewer. But if you stand on street level andlook down the road, the road actually fills much more of your field of view, as in the second sketch.

Here's a simple tool you can make that will help you learn perspective. At a craft store, buy a pre-cut mat (not too large or it will be wobbly in use - 8x10 is good), a set of dry-erase markers, and a sheet of mylar. Cut out a piece of mylar slightly smaller than the outer dimensions of the mat, and tape it firmly to the mat. Now you have a viewer you can mark on.

Set up a scene in your studio, or go outside and wander around until you find a pleasant scene. Now hold your viewer at arm's length, elbow locked as in the pencil experiment and view the scene through your viewer. Use the markers to draw the outlines of the objects and landscape exactly as it appears on your viewer. You should be able to produce a fairly accurate depiction of what is in front of you. And you can erase the marker and use your viewer on another scene.

This is a learning tool, of course - the goal is to teach to you SEE the angles and shapes in two dimensions and learn to ignore your extraneous knowledge that interferes with your ability to see.

One of the best books on the market for drawing is Betty Edwards' Drawing on the Right Side of the Brain. She is much better than I at describing why our logical left-brain so often interferes with our ability to see what's right under our noses. She also has a variety of exercises that will help you learn to get out of your left brain and into using the right side of your brain, the perceptive, creative side. Many people have found her book and other materials invaluable.