So David Hockney has declared the end of photography. Oh really? asks Joel Sternfeld, winner of the Citigroup photography prize: “The Hockney argument is as simplistic as saying that any non-fiction book is truthful. You can never lose sight of the fact that it’s authored. With a photograph, you are left with the same modes of interpretation as you are with a book. You ask: what do we know about the author and their background? What do I know about the subject?”