Mo-Ti, a Chinese philosopher in the 5th century BC, was the first to record seeing an upside-down but otherwise accurate image in a dark enclosure with a pinhole in its side. In Greece in the next century, during a solar eclipse, Aristotle noticed the crescent shape of the sun where light rays shined through dark foliage onto the dark ground. Alhazen, an Arab scholar and philosopher in the 10th century, noted that the larger the aperture, the fuzzier the image that formed.
In 1490, Leonardo da Vinci made one of his most important observations when using a camera obscura. He noted that objects reflect rays of light in all directions, which led him to explain how the eye works. Later, camera obscuras were used by Renaissance painters as basic drawing tools; by fortune tellers and magicians who fooled audiences into believing they were looking at the future; and in Victorian England, at seaside resorts where they were popular entertainment, often located in small octagonal buildings near beaches or on piers.
The only camera obscura available to the public in New England is at the Children's Museum of Maine, in Portland. When you enter the big box, about 14 feet by 20 feet, with walls 12 feet high, there's nothing to look at. Everything is painted the deep blue of a starless night sky except for two carpeted risers where visitors can sit or stand, and a round, white-topped table with mechanical controls attached. To see how the camera obscura works, you need to join a guided tour. Most here are led by Suzanne Kahn Eder, science coordinator, who tells young visitors it's like being inside an eyeball.
