Anamorphic picture of a man viewed with a conical mirror, 1700-1752.

An example of an anamorphic painting, a composition that can be only viewed with a special mirror that restores the deformed image. Painted upon an octagonal wooden base of oak, the oil painting is dated to the first half of the 18th century. The work of art remains unrecognisable until a conical or catoptrick metal mirror is placed at the centre of the picture. Examined from above a portrait of an oriental gentleman suddenly reveals itself. Paintings of this type were quite popular during the 18th century, especially anamorphic portraits that concealed the identity of the sitter from prying eyes.