In the beginning there was light…and darkness…and some spectacular pictures. In the 4th century B.C., Aristotle described a phenomenon where light entered a dark space through a small hole, somehow resulting in an upside down image of what was on the other side. During the Renaissance, artists like Leonardo da Vinci used the trick of light to create sketches. The 19th century saw tourists at Coney Island viewing the images as entertainment, while at the same time in Edinburgh, tourists were using the trick to spy on each other. This entertaining process is called camera obscura, which just means “darkened room.”
How does a camera obscura work? First, you need a dark room or box with a small hole on one end. Light from the other side enters the hole at an angle. Some rays of light are reflected from the tops of objects, like houses or trees, and shine downward. Rays being reflected from lower down, like cars or flowers, shine up. As all the light travels through the hole, the rays cross in the dark space and form an inverted (left to right and upside down) image. This is also how pinhole cameras and even eyes work. When we view things with our eyes, our brains correct the inverted image and make it appear right-side-up. Modern cameras use mirrors to fix the problem.
Want to make your own camera obscura? Visit the websites below:
Edinburgh’s Camera Obscura: http://camera-obscura.co.uk/camera_obscura/camera_make.asp
How to Make a Pinhole Camera: http://www.instructables.com/id/How-To-Make-A-Pinhole-Camera/?ALLSTEPS