Loss of Edges at a Distance; the Pupil and Vision
Aerial perspective, the apparent height of objects above and below the eye, and how pupil size changes seen size
This treatise page continues Leonardo's rules of aerial perspective: at greater distance the edges of middling-coloured bodies such as trees, tilled fields, walls and mountain rubble merge, and finally even the boundaries of light against dark are lost. Two precepts follow, one on how objects of equal height above or below the eye appear lower with distance while their parallel edges converge to a point, the other observing that the eye with the larger pupil sees larger figures, demonstrated by viewing a celestial body through a pinhole pricked in paper. The page carries text only, with no diagram.
On this page
Progressive loss of edges at increasing distance
At a second, greater distance the boundaries of middling-coloured bodies merge one into another, as with green things: trees, tilled ground, walls, and the rubble of mountains and rocks. Last of all to vanish are the edges where light meets dark and dark meets light. This ordering of what disappears first governs how depth is rendered.
Apparent height of equal bodies above and below the eye
Among things of equal height set above the eye, the one more remote appears lower; among those set below the eye, the one nearer the eye appears lower. Their parallel lateral edges converge toward a single point.
The larger pupil sees a larger figure; the pinhole test
The eye whose pupil is larger sees objects of larger figure. Looking at a celestial body through a small hole pricked in paper with a needle, only a small part of its light can act, so the body seems to shrink in proportion as the admitted light falls short of the whole.