Monthly Archives: June 2015
The following vocabulary terms are important in the study of perspective. I’m including them before we start a lesson on drawing in 1 or 2-point perspective, so that you are familiar with them. We have already discussed aerial perspective, so these terms are specific to linear perspective.
Linear perspective is the use of ellipses and converging lines to show depth. It involves foreshortening of parallel lines as they recede into the distance.
Foreshortening – An illusion of perspective when looking head-on to an object. It seems a lot shorter than it really is.
Ellipsis – A circular shape becomes oval when seen at an angle.
Eye level – This is a complete horizontal circle at your eye level as you turn your head or the horizon if you are at sea level. Everything in perspective is related to this line. All horizontal lines above eye level will slope downwards to the vanishing point, and all lines below eye level will slope upwards to meet at the vanishing point.
Horizon – The dividing line between sky and land – also known as eye level.
Picture Plane – An imaginary vertical plane at right angles to the line of sight upon which a drawing or painting is drafted. It can be regarded as the surface of your board or canvas. Think of it as a vertical sheet of clear glass at a short distance from you, through which you view your subject. What is seen on the picture plane is shaped by two factors: the height that the eye is from the ground and the distance the subject is from the eye.
Vanishing Point(s) – These are the points on the eye level on either side of the center of vision to which parallel lines going away from you converge and appear to vanish. Most of the time, these points occur outside the edges of your drawing board.
One Point Perspective – Also known as parallel perspective. If one side of the object is facing you, it is in one-point perspective. If you are standing in the middle of a street, edges are parallel, but seem to be meeting in the center – your center of vision (as in a railroad track).
Two Point Perspective – Also known as oblique perspective. If a corner of the object is the closest to you, the object is in two-point perspective. You will see two sides of the object at the same time, and the diagonals converge to a vanishing point left and a vanishing point right.
Three Point Perspective – A third point can come into play in perspective, but only when dealing with extreme heights or lows. Tall buildings are one example. In the case of looking up at a tall building (worm’s eye view) the edges of the building will not only recede to the two vanishing points (if looking at a corner), but there will be an upward (or downward) recession to a vanishing point. This vanishing point is always directly in front of the viewer at a 90 degree angle to the horizon line. If looking down at an object in three point perspective, it is referred to as a bird’s eye view.
Vanishing Trace or Sky Vanishing Point – A point used to determine roof lines. The point is extended from the horizon line.
Convergence Lines (also called orthogonal) are lines that converge at the vanishing point. These are any lines that are moving away from the viewer at an angle parallel to the direction that the viewer is looking. In the case of driving down a highway, these lines would be the edges of the highway as they move away from you forward into the distance.
Transversals – The horizontal lines of a “perspective pavement.” They get narrower as they go back into the distance.
Ground Plane – The plane stretching from the bottom edge of the picture plane to the horizon. It also forms the “ground” on which the viewer stands.
Viewpoint or Point of View – the fixed viewing position of the viewer. A normal viewpoint is at head height when the viewer is standing on the ground plane. If the spectator is standing on a stepladder, the horizon line will still be at eye level, but more of the ground plane will be visible. If the spectator’s viewing position is low down, the horizon line will be lower, and less of the ground plane will be visible.
LINEAR (THE USE OF LINES) PERSPECTIVE is what happens when buildings, trees, utility poles, etc. are seen in the picture place. It involves FORESHORTENING of parallel lines as they recede into the distance. The difficulty of foreshortening is what your left brain tells you. Rely instead on your right brain. YOU MUST DRAW WHAT YOU SEE, AND NOT WHAT YOU THINK YOU SEE! For example, you know that the trees seen in this sketch are the same size and height.
If you drew a line at top and bottom, it would be parallel, and never intersect.
But if you change your point of view and look at the trees from an angle, even though you know they are the same height, the one farthest away seems much smaller. The lines intersecting the tops and bottoms of the trees would converge at some point on the horizon line. (eye level). You have changed your position.
Locating the correct VANISHING POINTS (where those lines seem to converge) is the secret of understanding and using linear perspective. The horizon line or eye level changes if you change your position – If you crouched down, the eye level is lower – if you stand on a ladder, it would raise. Would you then see the tops or the bottoms of things?
Any other lines that are parallel to the tops and bottoms would also pass through the same vanishing points. Here is an example of a high eye level. The horizon line (eye level) is at the line of trees in the background.
But if I positioned myself lower while looking in the distance, the horizon line(eye level) would be at the bottom of the page, and I’d see a lot of sky, or in this case, ocean.
So this is just an introduction to linear perspective: more will follow.