Venice: Canaletto and His Rivals:

The Camera Obscura

Washington, DC—The camera obscura (Latin for "dark room") is an optical device that creates an image by focusing rays of light onto a screen or sheet of paper. Its benefits for artists were noted by the Venetian nobleman Daniele Barbaro in 1568: "There on the paper you will see the whole view as it really is, with its distances, its colors and shadows and motion, the clouds, the water twinkling, the birds flying. By holding the paper steady, you can trace the whole perspective with a pen."

A forerunner of the modern camera, the camera obscura consisted first of a room, then later of a portable box with a small opening in one side. Light reflected by objects in the natural world enters the box through a lens set into the opening and projects an image onto the opposite surface. The image, like one formed on the retina of the eye, is upside down and reversed. In the camera obscuras included in the exhibition, an angled mirror inside the box reflects the image right side up (though still reversed) onto a glass plate on top of the box. A piece of paper placed over the glass allows the projected image to be traced. Other models of the camera obscura varied in size and complexity.

View Painting and the Camera Obscura

Originally developed as a scientific instrument, the camera obscura appealed to artists who used it as an aid to drawing outdoors. While the optical principles behind the camera obscura had been known since antiquity, portable devices similar to the ones exhibited nearby were first available toward the end of the 16th century. Previous models would have been too unwieldy to be of practical use for the artist. The camera obscura would have helped artists render the correct perspective of views seen from eye level. Francesco Guardi was praised for his success in using the device to artistic advantage. Canaletto apparently used one as well. In his drawing View of Santa Maria Formosa toward the Right Side of the Square, the sheet of paper was not large enough to include the top of the bell tower, which floats to the right. If the top were superimposed onto the tower, it would fit precisely, suggesting that the artist simply moved the paper to catch the image projected from the lens of a camera obscura.

Camera Obscura Demonstration

The exhibition includes three modern camera obscuras that are similar to the historical models on view. A mirror inside each camera reflects the image of the East Building atrium onto the glass plate on top of the box. As with all camera obscuras of this kind, the image is upright but reversed.