I’m reading this amazing book by David Hockney, Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters. It is almost a dissertation on the use of optics, lenses, mirrors and projections in the 1400’s, 1500’s, and 1600’s. He uses visual evidence to prove that many masters used these optical tools to, in essence, trace. Now, lenses are lenses, they are just tools and the painters and their apprentices made the marks. Just as computers are tools today, the masters had their own set of tools that, in the hands of unskilled others, would not have helped. (My subject line is just a joke.) Actually, I was thinking of slatts but anyone interested in image making would appreciate this book. It is extremely thought provoking.