ArtSpeak
Horizon line: (also called eye level) An imaginary horizontal line that exists at your eye level and divides your line of vision.
One-point perspective: The technique of using a single vanishing point to create the illusion of a straight-on view into distant space. One-point perspective occurs when a face of an object (such as a cube) is closer to you than its sides.
Perspective: (sometimes called geometric or linear perspective) A technique made up of a precise series of rules that makes subjects in drawings appear to recede into distant space.
Perspective lines: Imaginary straight lines that extend from the edges of a drawing subject back to a vanishing point (or points) on the horizon line.
Vanishing point (VP): An imaginary point (or points) on the horizon line where perspective lines converge.
Many of Mother Nature's creations, such as trees and flowers, are somewhat forgiving of an artist's minor mistakes with perspective. However, people, animals, and most human-made objects need to be drawn accurately with perspective in order to appear proportionately correct.
Perspective can create the believable illusion of a third dimension on a flat piece of drawing paper. When used properly, perspective can also make representational drawings become visually correct and appear more realistic.
Perspective enables you to render a subject so it appears small when it is far away and larger when it is closer. You draw your subjects the size you see them within the moment and circumstances of your drawing, rather than the size you know them to be in objective reality.
For example, a horse that is standing on the far side of a large field will seem much smaller than what you know to be its true size.
In drawing, the horizon line has a different meaning than simply the line that separates the earth from the sky, or the line that the sun rises over every morning.
The horizon line is an imaginary line that is always at the level of your eyes. For example, to draw an object with one-point perspective, you can draw lines (called perspective lines) from points on your object to a single point on the horizon line.
This point (where perspective lines converge) is called the vanishing point (Figure 1).
Your eye level and the horizon line are one and the same (Figure 2).
Look straight ahead, to the right, and to the left, and you are looking directly at the horizon line. Wherever you go, from the top of the highest mountain to the bottom of the lowest valley, your horizon line will always be directly in front of you at eye level.
If you are scuba diving ten feet below the surface of the ocean, the horizon line is not above you, but exactly at your eye level. Fish may be swimming at, above, or below your eye level (your horizon line).
To take another example, your eye level remains the horizon line even in an airplane. Clouds can be in front of, above, or below your horizon line.
Drawings that are accurately rendered with perspective offer clues to let you know where is up, where is down, and where the horizon line (or your eye level) is. For instance, imagine boxes of varying sizes boxes floating in the air in front of you.
They are all facing in the same direction (Figure 3).
At eye level (middle row) you cannot see either the tops or the bottoms of the boxes.
Above eye level (top row), you can see the bottoms of the boxes but not the tops
Below eye level (bottom row), you can see the tops of the boxes but not the bottoms.
Challenge!
Find a small box or a thick book.
1. Hold the object directly in front of you with one side facing you until you can't see its top or bottom. The box is now at eye level and on the horizon line.
2. Move the object upwards until you can see its bottom. The box is now above your eye level and above the horizon line.
3. Now move the object downwards until you can see its top. The box is now below your eye level and below the horizon line.
Enjoy exploring how you see objects differently depending whether they are very close or very far away.
Also, embrace the fact that wherever you go, your horizon line always travels with you!
Challenge!
Drawing objects above the horizon line follows the same perspective rules as drawing objects below the horizon line. Have a look at Figures 4 and 5 - do you notice anything unusual about these two drawings?
They are the exact same drawing, but one is upside down.