Scientific research has shed new light on conventional ideas about art history, Charles Falco, optical sciences professor at the University of Arizona, told an audience at the Thayer School of Engineering on Friday afternoon. The development of realism during the Renaissance arose primarily from artists' reliance on optical devices, rather than on improvements in artistic technique alone, Falco said.
Falco presented evidence from his collaborative research with British artist David Hockney to argue that artists' use of optical devices, primarily concave mirrors, could account for the combination of both increased accuracy and systematic flaws in certain early Renaissance paintings.
According to Hockney and Falco's thesis, artists used optical devices to project magnified images of objects onto a canvas. The painter would then trace enough of the image on the canvas to outline elements of the object's optical perspective. The rest of the painting would then be finished with the addition of imagined or "eyeballed" elements, such as details or additional objects, Falco said. A painter might use optical devices several times for a single painting to focus on various parts of the scene, Falco said.
This technique allowed artists to capture important details of objects that could not have been captured by eyesight alone, Falco said. It also contributed to the increased attention to perspective and proportion that characterized 15th-century paintings, he said.
Optical science also explains the presence of idiosyncratic flaws in paintings where optical devices were used, Falco said. Refocusing mirrors to capture different parts of an object would change the magnification and vanishing point of the projected image, he said. The combination of multiple images in the final painting resulted in an imperfect geometric perspective, he said.
Painters began using optical devices in the late Middle Ages, when technological advances made acquiring concave mirrors cheap and quick, Falco said. Most scholars believe that artists did not begin using such devices until the late Renaissance, two centuries later, when refractive lens technology advanced, he said.
Falco supported his claim on the early use of optical devices with mathematical calculations demonstrating how theoretical images based on geometric perspectives do not correspond with the actual images in the paintings. These images could be explained by superimposing several images of the same object from different perspectives, resulting in an object that had not one, but several vanishing points, he said.
"Using optics is the only way to get perspective quantitatively wrong in the way that these artists got it wrong," Falco said.
Falco analyzed several well-known pieces from this period, including "Husband and Wife" by Lorenzo Lotto and "The Arnolfini Wedding" by Jan Van Eyck. The level of detail and the perspective flaws suggest that the paintings were created with the help of optics, Falco said.
Since the early Renaissance, Western artists have continued to use optics as a "powerful tool" to capture detail, Falco said, displaying a variety of paintings, ranging from works by 15th-century painter Rogier van der Weyden to a piece by 21st-century artist Chuck Close.
"Optical analysis has fundamentally affected our understanding of the past 600 years [of Western art]," Falco said.
