There's no argument that Hockney makes a very credible case. Unfortunately, the only way we can "support" it, pending someone's finding a "camera obscura" with the artists name written inside, is to propose all of the other ways the results might have come about - and see if he can knock them down.

In the category of "training wheels for artists," there seems to have been a resurgence recently of books featuring all of the old "penny postcards" that came out with the invention of photography, that were frequently described as "artists aids" to get past the censors.

Off to a jam for now.

John