A Treatise on Painting
by Leonardo da Vinci, translated by John Francis Rigaud
A Picture is to be viewed from one Point only
4005665A Treatise on Painting — A Picture is to be viewed from one Point onlyJohn Francis RigaudLeonardo da Vinci

Chap. CXIX.A Picture is to be viewed from one Point only.

This will be proved by one single example. If you mean to represent a round ball very high up, on a flat and perpendicular wall, it will be necessary to make it oblong, like the shape of an egg, and to place yourself (that is, the eye, or point of view) so far back, as that its outline or circumference may appear round.