Could the great Johannes Vermeer have used a camera to snap a photo of the "Girl with a Pearl Earring?"
Obviously, painters working in the 15th to early 19th century could not have had cameras and slide projectors at their disposal. Still, surface scientist Charles Falco claims there were other ways that early artists could directly cast images onto their canvases for tracing.
"A simple shaving mirror could have served as a lens," said Falco.
Projection With a Small Hole
Artist and art detective David Hockney has suggested that early artists used a device called a camera obscura to project images from real life.
A camera obscura is a dark box or even room with a small hole in one end. As light travels in straight lines through the hole, rather than scattering, they cross and form an upside-down image on a flat surface parallel to the hole.
Students today might be familiar with the box-like tool that's commonly used to view eclipses of the sun. But there's also evidence that people had caught onto the trick as early as the 5th century B.C.
Records show that the ancient Chinese philosopher Mo-Ti marveled at how a darkened room with a pinhole became a "collecting place" for images.
Art by Mirrors
Falco explains the camera obscura can take an even simpler form. He says a concave mirror (which has a lens that is curved outwards) reflects and focuses light upside-down the same way on a parallel screen.
"If I want to reflect the scene outside my window I'd just have to hold the mirror up to the window at a certain angle and it would be reflected upside down on my canvas," he said.
Falco believes many early artists may have used concave mirrors to reflect and outline figures upside-down on their canvases. They then flipped the canvases to fill in colors and shading.
Walter Liedtke, a Vermeer scholar and a curator at New York's Metropolitan Museum of Art, is not convinced.
He says features in Vermeer's work — such as marble floors that could never have been inside the artist's own home — prove the 17th century artist didn't depend on images to trace his works.
"Vermeer's art was made by style and discrimination, not just transcription of what was in front of him," he said.
The Magic Lantern
Philadelphia Museum of Art curator Mark Tucker says at least one later artist, Thomas Eakins, used more sophisticated technology — the magic lantern — to trace photographs on his canvas.
Invented in the late 19th century, the magic lantern projected hand-colored glass slides onto a larger screen (these slides could be adopted from photographs).
To project images, the device used light created when oxygen and hydrogen were squirted on a piece of limestone. As the gases were lit, the limestone turned incandescent and produced a powerful light.
Although some art scholars have recoiled at the suggestion that Eakins traced his work, Tucker argues it only adds to the artist's reputation.
"I think he was a clever man," he said. "It just means he knew how to make great use of technology."