The Mirror in Arnolfini ’ S Room

When we consider the grand trajectory of Western painting, we see something very interesting taking place at the dawn of the Renaissance. Before roughly 1425, most images were rather stylized, even schematic, but afterward we see paintings that have an almost photographic realism. For instance, Portrait of Giovanni Arnolfi ni and His Wife, by the early Renaissance master Jan van Eyck (1390?–1441), reveals a threedimensionality, presence, individuality and psychological depth lacking in earlier works. For the fi rst time, we fi nd portraits that really look like us. What happened? In seeking to explain the emergence of this remarkable new art, or ars nova as it was called, the celebrated contemporary artist David Hockney came up with a bold and controversial theory. He claimed that Renaissance paintings look realistic—possessing what he called “the optical look”—because artists used lenses and mirrors to project images onto canvases or similar surfaces and then trace and paint over the results. [Editors’ note: This theory is set forth most completely in Hockney’s 2001 book Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters.] It is well known that in the 18th and 19th centuries some painters made use of images optically projected onto their canvases. But Hockney’s theory would push the earliest date a quarter of a millennium earlier still. And so important are these optical instruments and techniques to his theory that Hockney says the history of art from that time is intimately linked with the history of optics itself.