To the Editor,
We can all be grateful that David Hockney has, it seems, retreated
from his controversial claim that painters as early as 1430 actually
traced over images projected by concave mirrors onto their
canvases while executing their works, a quarter millennium before
we have secure evidence that artists did so. His current view
comports with the consensus of international experts who, bolstered
by rigorous image analyses and dramatic physical discoveries,
reject that projection praxis claim. For instance, the largest
scholarly investigation of Hockney's idea, a three-day symposium
in Ghent in November 2003 (which I did not attend), concluded:
"With respect to the 15th century, the idea that Flemish
realism could be derived from the use of mirrors was roundly rejected."
I thank Lawrence Wechsler, Hockney's long-time personal friend
and advocate, for mentioning my role in such analyses ["Vanishing
Point," June], though many others deserve significant credit.
Now that this portion of the debate is behind us I can confess
that I'm just a bit disappointed: Hockney's tracing conjecture
was captivating and very cool; alas, it simply could not meet
the burden of proof.
But now it appears that the technical analyses that energized
Hockney's efforts no longer matter to him; he stresses his main
point all along was that "even just to see [a projection]
was to use it." Many of us scholars who have considered
this alternate speculation find it hard if not impossible to test
in a satisfactory manner, given that the technical optical, image
and physical evidence is of little relevance and the more informal
or "impressionistic" evidence is highly ambiguous, even
to expert art historians and artists. Hockney's case here is severely
weakened, moreover, by the fact that there is no documentary record
anyone in the early Renaissance--optical scientists, artists,
mirror makers, patrons, etc.--ever saw an image of an illuminated
object projected onto a screen by a lens or concave mirror. There
are, furthermore, more secure and plausible alternate explanations
for the rise in the "optical" style of painting, such
as the contemporaneous rise in the use of spectacles, of oil paint,
and of artists' aids for producing images in single point perspective,
not to mention many social, cultural and economic forces.
Wechsler's lavish article serves as milestone, marking the turn from the "tracing" claim to the "influence" claim, which should garner interest and debate among traditional art historians. I'm glad that careful, rigorous science played a role in clarifying the scope of Hockney's perceptive speculations and helped to bring us to that milestone.
David G. Stork
Portola Valley, CA
Chief Scientist
Ricoh Innovations
Consulting Professor of Electrical Engineering
Stanford University