Hoodwinked by Hockney? - Letters

To the Editors:

As one of the two scientists at the December "Art and Optics" symposium who analyzed (and rejected) David Hockney's bold theory on the use of optical devices by old masters, I consider David L. Sweet's review of Secret Knowledge [A.i.A., Apr. '02] greatly surprising--because his is the first I've read that finds Hockney persuasive. Sweet conveniently excuses Hockey from the obligation to frame a coherent argument, since the artist writes "free of the professional constraints of the traditional scholar." But if we are to fairly judge the theory, such constraints must then pass to reviewers; it is here that Sweet falls short.

For example, Sweet does not point out that murals, ceilings, self-portraits and moving objects all elude Hockney's mirror-projection method; that, because he worked in dark cellars by artificial light, Caravaggio would have been forced to use over 1,000 candles at a time; or that virtually all brushstrokes in Renaissance paintings are downward, thus contradicting the theory that these works were executed at least in part upside down.

Following Hockney, Sweet correctly notes the slight anamorphic distortions that occur in some paintings, but these can arise when artists paint with their canvases at slight angles. Indeed, the first deliberate examples, in Leonardo's Codex Atlanticus, were almost surely created this way. Likewise, minor perspective inconsistencies, such as in the coin box in Holbein's portrait Georg Gisze, can be explained naturally by the artist's moving forward to get a better view. Similar explanations apply to paintings from northern Europe that display the so-called collagist perspective.

Sweet mentions that concave mirrors were available in the 15th century, but not that we lack any evidence for the long-focal-length mirrors demanded by Hockney's theory. Moreover, while simple by today's standards, such mirrors--in their manufacture, testing and cast-image employment--would have represented the most sophisticated optical engineering on the planet in 1430, making them the Hubble telescope of their day. Perspective constructions, familiar to every school-child with a ruler and pencil, consumed some of the greatest mathematical, architectural and artistic minds of the 15th century and led to numerous scholarly treatises. In contrast, despite historical records of all manner of obscure optical and drawing devices, from anamorphic mirrors and the bacolo of Euclid to zoetropes and zograscopes, there is no corroboratory evidence for the projective use of concave mirrors in art--not a single artifact or passing mention by a scientist, portrait subject, patron, guildsman, Inquisitor or artist. The claim that trade secrecy or the Inquisition suppressed the "secret knowledge" is extremely implausible. Such secrecy would involve hundreds of independent or rivalrous "co-conspirators" and tens of thousands of complicit observers over centuries.

Hockney's sumptuous book hopes to persuade by visual example but occassionally backfires. The portraits by Durer and Hals reproduced in Sweet's review show that Hockney's "opticality" may be due to surfaces, shading and subtleties in color rather than contour. The rendering of surfaces is never aided by tracing outlines in the manner Hockney demonstrates. And if you try to paint directly under optical projections, creating such surfaces is impeded significantly.

The central problem with Hockney's book, and Sweet's review, is that alternate explanations are either overlooked or dismissed without adequate examination. Consider a few non-optical factors that might have yielded "opticality" in the early Renaissance: Masolino and van Eyck were experimenting with oil paint and its enhanced contrast and saturation; geometrical perspective gave rise to a new interest in realism; trading between the Medici and the Burgundian court increased the demand for accurate portraits; the Popes returned to Rome from Avignon and began a renovation of Roman art and architecture that opened their eyes to the perceived physical world rather than the conceived spiritual one; eye-glasses first became popular, allowing myopic artists to see with a new clarity (an "optical" explanation quite distinct from Hockney's).

It falls to Hockney and his supporters to dispose of traditional explanations and the numerous non-optical explanations for detailed effects in individual paintings--a task as yet unaccomplished.

David G. Stork
Portola Valley, Calif.

COPYRIGHT 2002 Brant Publications, Inc.
COPYRIGHT 2002 Gale Group