From The Keppler Files: May, 1967

While the main concern of any piece of equipment or sensitive material is the resulting photograph or photographs, inevitably a photographer suspicions that a friend's lens is sharper, another developer is faster, an alternative color film is truer, a black-and-white film is less grainy and so on. And if the photographer really wants with all his heart to believe that this is so, he will always come up with proof of it in negative, transparency or print form. I see plenty of "proofs" and 99 out of 100 are just as valid as a gold-covered lead brick.