The Camera Obscura

Joe Boyle, The Book of Alternative Photographic Processes. Men from a nomadic tribe in the Middle East utilizing the camera obscura.

The Camera Obscura was an ancient predecessor to the modern-day camera. While the term “camera obscura” was not coined until the 17^th century, meaning “dark room” in Latin, the idea dates back to the 5^th century BC. Mo-Ti, a Chinese philosopher, observed in the 5^th century BC that he could recreate an image through a tiny hole in a screen shining into a darkened room. When light rays, which travel in straight lines, pass through a small hole in a thin object do not scatter as they do with larger openings like windows; instead, the light rays act as if there was a funnel on either side of the hole. The rays converge to pass through the hole and then spread out again, only the image will be upside down and backwards.

In the 10^th century CE, the Islamic scholar Alhazen notes nomadic tribes of the Middle East utilizing the camera obscura for surveillance. Because of the intense heat during the day, the wanderers would rest during the day and travel at night when conditions were more favorable. They were able to watch the horizon for possible threats or family members through the fronts of their tents, but that allowed them only one side of view. By poking small holes in the other three sides and rigging them with pieces of cloth to work as shutters, they could watch each side one at a time through the process Mo-Ti, Aristotle, and Alhazen himself described.

One of my three pinhole cameras, which use the idea of the camera obscura

Usually camera obscuras were made in large rooms with a nice view. They were not extremely popular until they were turned into drawing aids with the help of lenses and mirrors in the 16^th century. This development allowed artists to gain better perspective in their drawings and study the human form more closely. Eventually this technology led to the development of photography in 1839. Though rare, people still use the idea of the camera obscura today in pinhole cameras.