News: Was Caravaggio Using a Lens?

According to art historian David Hockney, he was. Hockney claims that Caravaggio used a lens or other optical device to help paint his masterpieces, like his Bacchus on the right, the argument for which he outlines in his book, Secret Knowlege.
 
This view, however, is contended by Andrew Graham-Dixon, an art historian in his own right and BBC2 Culture Show presenter who says: “Caravaggio never used lenses. He had a convex mirror, but he certainly didn’t go in for the complex set-ups that have been hypothesised. Caravaggio’s revolution is making humanity the centre of his art. He went to the pub. He mixed with prostitutes.”
 
Graham-Dixon is currently promoting his own book on Caravaggio entitled The Art of Caravaggio: A Life Sacred and Profane and is working on a new series called The Art of Germany for tv to be shown in 2011: “There is a lot of Hitler in this,” he said. “I take the view a lot of the terrible things he did stemmed from his obsession with visual art.”