Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters (review)

Years ago, I was approached by a law firm to testify as an expert witness. They showed me a drawing and asked if I knew, simply by looking at it, if it had been traced or drawn unaided. I responded without hesitation because I believed I could easily tell. I recalled that incident as I read this book, since much of David Hockney's "evidence" for its hypothesis rests on his claim to be able to tell a drawing made freehand (by the process he calls "eyeballing" or "groping") from one that was traced using optical aids. Hockney (b. 1937) is a British-born painter who became famous in the 1960s as a pop artist. He has since moved on to other work (notably, using Polaroid photography), has settled in California and is among the most interesting artists today. He not only creates art, but also studies it in ways that one might expect of a scholar.

In this large-sized, exuberant opus, filled with breathtaking, full-color details, he argues that he, as an artist, has noticed that something is woefully wrong in the standard account of the progress of art since the 1400s. It is widely assumed, for example, that European Old Masters, beginning with the early Renaissance, made drawings and paintings of models from life, freehand and unaided, meaning that whatever effects they obtained were achieved by their use of perspective, from their studies of anatomy and from a new-found attention to worldly forms. But, as Hockney demonstrates, Renaissance "photorealism" emerged with amazing rapidity from Gothic innocence, which prompts him to posit an alternate cause: He thinks that artists used optical aids (simple concave mirrors at first, then lenses and cameras obscura) as early as the 15th century ("the big change occurred sometime around 1420-1430," he writes). Not all, but the bulk of his evidence comes from merely looking carefully at reproductions of paintings by Van Eyck, Holbein, Carravagio, Velasquez, Vermeer, Ingres and dozens of others. Substantial skill is required to trace with an optical instrument (even today, which Hockney confirms by attempting to draw, not very successfully, using a convex mirror and a camera lucida), so that he repeatedly cautions (contrary to what is now commonly thought) that tracing in art is not cheating, and his discovery in no way belittles the work of the Old Masters (but of course, that is exactly where all of this leads). Further, he does not claim that "all artists used optics," only that in a surprisingly short time period "the lens had become so dominant that its image was now the model for all [European] painting." Assuming that Hockney's conjecture is true, a number of irksome anomalies in Old Master paintings become explainable, such as the smallness but accuracy of certain of their preparatory drawings; the precision with which they could render the folds of highly patterned cloth drapery, suits of armor and the complex surfaces of globes, lutes, and melons ("the lute of the fruit world"); the abundance of left-handed artist's models (right-handers, Hockney surmises, reversed by the lens of the drawing machine); and the coexistence of offset, mismatched points of view, as if key elements in the picture had been drawn separately with an optical instrument, then montaged together to form a tableau. It may even explain the dramatic juxtaposition of highlight and shadow in the paintings of Caravaggio, Velasquez, Rembrandt, Georges de la Tour and others.

I should explain that for many years, long before this book began, there was little doubt among art historians that some artists had experimented with drawing devices (Vermeer, for example, is said to have used a camera obscura); we know this because there are pictures of these devices by Leonardo, Dürer and others, even Van Gogh. So the real contribution of Hockney (whose unsung collaborator on this project was a physics professor named Charles Falco) may be...