Double Take

Although somewhat dismissed by the contemporary art world as gimmicky, works that incorporate optical illusions remain immensely popular with the general public. Perhaps it speaks to our inherent need for something slightly magical in our everyday lives.

- BRUCE SCOTT

When you think about it, all art that attempts to represent the three-dimensional world on a two-dimensional surface - be it a wall, a canvas, a board, a piece of paper or a stretch of sidewalk - is an illusion. The artist uses certain systems and techniques to create the impression of space, depth and movement, and the better their skills are the more we, the viewer, believe in the reality of these worlds.

Interestingly, before the 14th century western artists made little attempt to realistically depict a three-dimensional world, which is why the art of the Byzantine, Medieval and Gothic periods seem so odd to the modern viewer. Creating the illusion of depth and space was not the priority back then. Chinese art of this time - on the other hand tended to merely "suggest" recession across space with careful fades and blurs.

By the 13th century, painters in Italy such as Giotto and Duccio began using heavy shadowing to give the illusion of depth and volume in their art, and thus an early form of perspective was born. The first known use of true linear perspective in Western art, however, is generally credited to the Florentine architect Fillipo Brunelleshi, who in 1415 depicted the Baptistery in Florence from the front gate using "vanishing points" - in which all lines converge, at eye level, on the horizon.

Brunelleshi's painting essentially introduced a wholly new concept, and many Italian artists started to use linear perspective soon afterwards.

By the late 15th century, European artists had mastered linear perspective and were able to create strikingly realistic worlds. Of course, as soon as this effect became widespread, artists also started playing with it, and Andrea Mantegna's famous Oculus of the Bridal Chamber, in the Ducal Palace of Mantua (1465-1474), attempts to make it seem as though a host cherubs and other figures are staring down at one from an open window in the ceiling.