Perspective-projection-albrecht-drer-science-source, Albrecht Dürer, 1 January 1538

Dürer woodcut of jacob de keyser's invention. With de keyser's device, the artist's viewpoint was fixed by an eye hook inserted in the wall. This was joined by a silk string to a gun-sight style instrument, with a pointed vertical element at the front and a peephole at the back. The artist aimed at the object and traced its outline on the glass, keeping the eyepiece aligned with the string to maintain the correct angle of vision. Date: 1 January 1538.