Foreshortening of a Pencil

From Draw Like da Vinci, p. 46–47: Foreshortening: The illusion of shortening occurs when an object is directed towards you or away from you; this distortion is foreshortening. Foreshortening is a device for creating drama, movement and depth – there are many examples in Leonardo da Vinci's work, such as the arm, hand and fingers of the Virgin [in The Virgin of the Rocks, National Gallery, London].

Foreshortening can be demonstrated by looking end-on at a pencil held directly in front of you and then gradually tilting the pencil so that you see more and more of its length. The actual length is seen undistorted only when the two ends are equidistant from your line of vision. See how a person's arm appears to become shorter as it is raised to point a finger at you.

When Leonardo demonstrates proportion, he draws an unforeshortened view. The arms and legs of Vitruvian Man, Galleries of the Academy of Venice (Gallerie dell'Accademia di Venezia)are seen in their full extent.