To the editor,

As one of the first independent scientists invited to evaluate David Hockney's controversial theory that early Renaissance masters traced optically projected images, I was heartened to read Steven C. Munson's whithering critique of this flawed theory ["Rembrandt& the Artist's Touch," March 2007]. While indeed Hockney gives little credible evidence in his beautiful book, Secret Knowledge, in the six years since its publication he and his colleage have tried to provide more compelling evidence. To date, however, at least seven scientists, seven historians of optics or art, and one curator have published peer-reviewed scholarly rejections and new evidence rebutting the theory. A four-day symposium in Ghent in 2003 (which I did not attend) rejected the theory in no uncertain terms; to my knowledge noone has published peer-reviewed research supporting the theory.

But even as we close the books on this controversy, we should note that it has led to a number of new techniques in scientific image analysis; these and others are shedding light elsewhere in the study of art, such as the authentication of Jackson Pollock's drip paintings, attribution in paintings by Perugino and Robert Campin, and on new ways to date prints and etchings, such as those of Rembrandt. Perhaps Hockney's greatest legacy in this regard is to have served as catalyst for the development and acceptance of such methods, informed by both the scientist's rigor and the humanist's connoisseurship.

--David G. Stork, PhD
Chief Scientist, Ricoh Innovations
Lecturer, Stanford University
www.diatrope.com/~stork/FAQs.html