Apr 8, 2012
A Guide to Perspective Distortion
Introduction
There are many places on the Internet that try to explain perspective distortion. Most of these sites are technically accurate but not all that helpful in understanding how or why to use perpendicular distortion. They are more akin to a camera manual explaining how to change the shutter speed on a camera. This is important information but still you don't know why.
Perspective distortion (sometimes called distance compression, which isn't a good name) is something we learn about soon after we can focus. We learn that it is part of the world we see. The brain incorporates it into the model of what is around us and we use it to judge size/distances when we are not using binocular vision for this. To paraphrase a rock star and brain surgeon: (Buckaroo Banzai) "wherever you look, there it is". What perspective distortion you get is determined by where the viewing is taking place and as such is a continuum from near to far.