David Hockney certainly raises a compelling argument for his theory of the “old Masters” using lenses and / or mirrors as tools of the trade, so to speak. His thorough research and painstaking reenactments are certainly impressive and as he states, it seems that science is on his side.
I personally would not be surprised to find that Caravaggio, da Vinci, Van Eyck and other painters utilized whatever tools might have been available to create their masterpieces. That would not be unlike having oils to paint with, but you stuck to watercolors because “that’s what I’ve always done”. It was a time of change in Europe. There were many inventions, new ways of thought that were being explored. Science was new and excited and revealing wonderful things to those who chose to embrace it. Why not embrace this new, exciting way to capture an image?
I believe that many art lovers and Art Historians would feel a bit betrayed – kind of like if you were to find out that not only were Milli Vanilli lip-syncing, but the Beatles were too. If they believe this theory of Hockneys, they are saying the “old Masters” weren’t the great phenomenon that everyone thought they were – a group of obviously highly gifted artists with an uncanny ability to create a perfectly drawn likeness – in perfect scale – which would be more believable if they had been autistic or something of the sort but then would they have even been gift the chance to integrate with society or to create fabulous works of art? Today – how many people in the world can draw a likeness with perfect scale and geometry? And we have how many billions of people on this earth? Why would they have had anymore back then? The Renaissance was a time of change in the world and I think these intelligent men might very well have mixed talent with science. Despite everything, these “old Masters” were greatly talented and what they did affected the world and the people in it and continue to do so. Contemporary art shows that color, texture, shadow, proportion adds as much or more to a work than perfect likeness. Art Historians don’t need to get horribly shook up about it.