ABSTRACT
The point of observation in ecological optics might seem to be the equivalent of the station point in perspective geometry, the kind of perspective used in the making of a representative painting. The station point is the point of projection for the picture plane on which the scene is projected. But the terms are not at all equivalent and should not be confused, as we shall see. A station point has to be stationary. It cannot move relative to the world, and it must not move relative to the picture plane. But a point of observation is never stationary, except as a limiting case. Observers move about in the environment, and observation is typically made from a moving position.
