The same style of argument in Lotto's Husband and wife, where Hockney and Falco fit the image data to the astounding precision of three significant figures, showing they believe Lotto accurately—even "slavishly"—traced a projected image. But now that the severe problems with their explanation are clear, will they retreat from their explanation to tell us that Hockney's "artistic vision" has changed and that Lotto did not "slavishly" trace a projected image? One they previously claimed was traced to a precision of three significant figures?
Although this is a fairly good summary of the Hockney and Falco theory, it contains a few errors. It also sidesteps the most important issue raised by Hockney's argument that lensing devices were secretly used by many Old Master painters--namely, the philosophical question of whether it matters, in terms of our judgment of quality, if certain Old Master painters probably used lensing devices.
Hockney–Falco thesis - Wikipedia, the free encyclopedia
One problem facing Hockney and Falco is the lack of evidence among optical sources to support their claim that artists used image-projection by the early 1400s. After all, if quattrocento artists knew about image-projection, they must have learned about it from experts in the field, and no one was more expert at the time than Perspectivist opticians. As I argue in this paper, however, Perspectivist reflection-analysis posed certain theoretical and conceptual constraints that would have prevented Perspectivist opticians from recognizing, much less understanding, image-projection. Their silence on this matter is therefore not evidence against the Hockney-Falco thesis.