Before I leave the subject of Avedon, I should add a footnote on the tone of slight defensiveness I adopted in describing his photographic technique.   One of the reasons was that he had asked if the exhibition could be reviewed – preferably at length – by David Sylvester.   I telephoned Sylvester and put the request to him.   He said that he would consider it.   Avedon was pleased.   Sylvester then came in to see the exhibition and hated it.   I thought that he had written something about it, but I have discovered that this was a false memory.   But I felt badly for Avedon, who had so wanted something written in depth about his work and had not paid attention to the fact (or maybe regarded it as a challenge) that Sylvester almost never wrote about photography and didn’t regard it as an art.