Research by a UA optics professor suggests some of the Renaissance's grand masters had a little help with their paintings.
Charles Falco, an optical science professor, said his research shows painters as early as the 15th century used lenses and mirrors to achieve an unprecedented level of realism.
Falco collaborated with British artist David Hockney to come up with a thesis that has angered some art purists.
""Different people have different types of objections,"" Falco said.
The Hockney-Falco Thesis posits that the sharp rise in realistic painting during the dawn of the Renaissance is due to optical painting aids.
""Some people will go to their grave saying, 'This is not true,'"" Falco said.
This flies in the face of the belief that
It's very important to realize that these paintings are not photographs. These are collages; some features were painted with optics, others were not.
optical science professor
""All of the evidence is in the paintings themselves,"" Falco said.
A group of people even picketed the Metropolitan Museum of Art, angered at Falco's findings.
""You don't normally get this level of interest,"" Falco said.
Falco demonstrated his proposed method by shining a bright light on a model of a skull. A small concave mirror projected an upside down image of the skull on a nearby wall.
""All that's required are capturing key features upside down,"" Falco said.
Artists using this method would use the flipped image to copy as many key features as the artist needed and then fill in the gaps with paint, Falco said.
""It's very important to realize that these paintings are not photographs,"" Falco said. ""These are collages; some features were painted with optics, others were not.""
Falco said evidence of this painting method appears in such paintings as Jan Van Eyck's 1434 painting, ""The Arnolfini Portrait.""
The arms of the chandelier at the top of the painting appear in perfect perspective, something Falco showed by creating a 3D model.
""It's not magic, it's optical science,"" Falco said.
The decorations on the arm of the chandelier do not match up when rendered electronically, something Falco points out as one of the gaps Van Eyck filled in freehand.
""These images were not perfect, but they were as good as perspective as one can get with a hand-painted object,"" Falco said.
Students like Amy Winkler, an optical science graduate student, might become more interested in the optical aspect of art thanks to Falco's research.
""I thought it was really interesting how complex it was,"" Winkler said. ""I think I'm really going to look for things now.""
The interest in Falco's research has prompted a ""professor's dream,"" people interested in learning optics in order to understand his work.
""It has allowed me to reach crowds that I wouldn't normally reach,"" Falco said.
The ""Rosetta Stone"" of Falco's research appears in Lorenzo Lotto's 1543 portrait, ""Husband and Wife.""
The design on the carpet in the foreground of the painting appears in three different perspectives, Falco said.
Using a rug at home and a ruler, Falco took two pictures, one focusing on the foreground and one focusing on the background. When the two focused portions were combined, the ruler seemed to bend because it was being seen in two different perspectives, Falco said.
This proves artists who used lenses to detail certain areas copied small portions of the area at one time, Falco said.
A slip-up in the anamorphic skull in Hans Holbein's 1533 painting ""The Ambassadors"" demonstrates this idea. Holbein mistakenly painted one zone of the skull twice, Falco said.
Falco said although the scientific evidence can be found in the paintings, there are no artists' diaries from that era that describe the use of lenses.
In Leonardo da Vinci's case, the half of his journals that survived do not describe using projected images to trace a picture. However, these journals do describe grinding concave mirrors together, Falco said.
There is also no written documentation of evidence of lens use, said Pia Cuneo, an art history professor.
Artists at that time were more likely to take up painting because they inherited the materials and the workshop and not because of a passion for it, Cuneo said.
""These were individuals who became painters because it was a family business,"" Cuneo said. ""At that time, to be a painter was to be a craftsman.""
Artists during the 15th century were regarded more as craftsmen rather than as learned men, Cuneo said.
""They were educated to a certain degree, but not to a very high degree,"" Cuneo said.
Painters who were employed by the court, such as Van Eyck, were assumed to have a slightly higher level of education, Cuneo said.