Drawing tutorial 027 - Basics(Part 5) - Perspective

When we start to draw things from memory as beginner we tend to draw them in a way we perceived the object in our brain rather than how we saw it. A good example is to draw hair - we are tempted  to draw hair by hair. We know that individual hairs make the whole volume of the so called 'hair' on the head. But do we generally see individual hair?

In a similar way, we as a beginner, tend to miss how we see dimensions such as length, breadth and height of objects around us. As a result, we draw a rectangular building as a rectangle. It may sound crazy, but we do not see it as a rectangle but our brain perceives it that way.

How big an object appears to us depends on the angle that is created by the object in our eye. We have experienced it. It is for this reason, things appear smaller when its away. Our brain can still perceive, in most cases, the actual size of the object by comparing other parameters such as how far the object is, known objects around it, Colour variation etc.

While viewing objects that are big enough so that one part of it is close enough to the observer and the end reach is far away, it creates a interesting distortion in the viewers eye. This distortion of dimension follows the rule of angle that we discussed above. Smaller the angle, smaller the object.

However, when the same object is viewed from a distance so that the angular variation is not significant, we do not see the distortion. This creates an image of the object in the brain. When we see it in a distorted way we still perceive its actual dimensions. While drawing we tend to draw this perceived image. 

In the above picture, the buildings are similar shaped but the distortion is visible. The lower side of the building in the right is wider than its top. This happens with almost everything big and long/high we see in our day to day life. A railway track tends to vanish to a point, a road narrows down as far from the viewer it goes, tree heights seem to get reduced.

The basic tenet is that if comparable sides of an object can create different angle to the viewer, the object will look distorted in comparison to its original shape. Lets see the example below:

Though the ruler is not a big object, its two ends create different viewing angles to the viewer. This creates the illusion that its far end is narrower than the near end. The following illustration should make things clearer

 

In the drawing above, two poles though of same height creates different viewing angles. This when represented from viewers perspective will look like the drawing below:

The above discussion gives the basic theory of perspective in drawing. The bottomline is that objects of same size (measure it by height or breadth as the case may be) looks smaller when away from the viewer than when it is closer.

This creates interesting visual effects to the viewer. When drawn with perspective in mind, the drawing is more lively because of more depth to the drawing and doesn't look linear or flat. We will see some sketches with perspective latter in this lesson but lets now see different perspectives that are applied in drawing.

1. Single point perspective
2. Two point perspective
3. Three point perspective

There are more like four and five point perspective, however those are not so common in drawing. Moreover, rather than adding depth and visual appeal the later two perspectives twist the reality too much which are only special cases and may be studied as advanced perspective theories.

While discussing perspective, two drawing terminologies are often referred, Vanishing point and horizon line. A vanishing point is that point at which the objects create so small a viewing angle that they can be practically rendered as a point. Horizon line is the horizontal line drawn at the eye level of the viewer. The basic principal is that the vanishing point always falls on the horizon line. For single point perspective, there is only one vanishing point, for two point perspective there are two vanishing points and similarly for three point perspective there are three vanishing points. 

We will discuss each of these perspective drawings in subsequent tutorials. Lets see how the perspective drawings look like.

We will discuss on single point perspective in detail in next post.