Photography didn't develop overnight. It was a process.

Photography didn't develop overnight. It was a process.

Camera Obscura

The first "cameras" weren't cameras at all, but really big drawing tools. A "camera obscura" was basically a giant dark box with a small hole at one end. The light shining through would project an upside-down image of the outside world within the box. Most "cameras" were big enough that artists could sit down inside them and place a mirror at a 45-degree angle to the projected image, therefore giving themselves a right-side-up view. Then they could simply trace that image onto canvas or paper.

Abu Ali Al-hasen Ibn Alhasen, an Islamic astronomer and mathematician, is often credited with inventing the technique in the 10th or 11th century, and he noted, wisely, that the inverted image produced by the camera obscura might be related to the way the eye turns images upside down on the retina. But the idea of camera obscura also seems to have occurred to earlier thinkers, including Aristotle.

Later scientists such as Leonardo da Vinci and Johannes Kepler (who coined the term meaning "dark chamber") also made use of the technique. And Daniel Barbaro, a contemporary of da Vinci's, wrote extensively about how to make use of it: "Close all shutters and doors until no light enters the camera except through the lens, and opposite hold a piece of paper, which you move forward and backward until the scene appears in the sharpest detail. 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."

Sorry Barbaro. We'd rather have you draw us a picture than go on for another thousand words.

Science Experiments

Photography didn't advance much beyond tracing until the 1600s, when three key developments around Europe set in motion the process of capturing an image:

1. In 1614 Angelo Sala, an Italian, found that powered nitrate of silver turned black after spending time in the hot sun. (Now we're getting somewhere.)

2. Robert Boyle, a Brit, noted in 1667 that silver chloride turned dark after being exposed to air. (The key exposure was to light, not air per se, but give the guy a break - he was close.)

3. In 1727, Johann Heinrich Schulze, a German, put a white, powdery mixture of silver nitrate and chalk into a glass bottle, covered part of it with paper stencils, and stuck it in a window. The exposed parts got darker; those covered by the stencils remained white. Schulze had finally pinned the effect on exposure to light. Alas, he wrote, "Many who were curious about the experiment but ignorant of its nature took occasion to attribute the thing to some sort of trick."

Adapted from In the Beginning (HarperCollins), available at leading bookstores. For a daily dose of quirky fun visit MentalFloss.com and check out mental_floss magazine at your local newsstand.