Look back in Ingres
This piece in the New York Times is about a symposium featuring painter David Hockney and some art history scholars. Hockney reckoned the Old Masters used more lenses, mirrors and other optical aids than had been thought. Not everyone agreed — the debate sounds like fun.
I think Susan Sontag produced the best quip. To say that there were no great painters before optical devices, she said, is like saying there were no great lovers before Viagra. (Thanks to Arts & Letters for the link).