SIGHTING PERSPECTIVE
We work on two types of perspective in this course. The first is the more familiar
linear perspective, a system developed during the Renaissance for showing an
illusion of depth, particularly in geometric forms such as architecture. The
second, a kind of visual perspective, uses a technique called sighting.
In any kind of perspective, the salient issue is that of the angle of a form. Linear
perspective uses vanishing points as a means to get the angles to appear correct
and convincing. However, linear perspective is based upon a system, not upon
perception. Sighting or visual perspective is a technique that will enable you to
get the angles to look correct in something you see in front of you without the use
of a vanishing point. Both methods are important to know, and often combining
aspects of both will produce the best result.
To sight an angle on an object, such as a box or building, hold your pencil at a
horizontal angle out in front of you and compare the horizontal line with the angle
you are drawing. Closing one eye to make things appear flatter can help. You
should be able to view the angle more clearly this way in relation to a horizontal
line. Now look down at your drawing and compare the angle of the drawn line to
what you see. You can sketch a horizontal line above the perspective angle to
help you compare. By going back and forth, you should be able to estimate all
the angles in the object very clearly.
A natural tendency is to make the top of the box too wide. This is because we
know in our memory that it is a rectangular shape when viewed straight on, so it
seems that is how it should look. But when viewed in an extreme perspective,
objects are very distorted. Sighting will help you to see these distortions more
accurately.