For centuries artists had used the camera obscura, a dark box in which a lens throws an image onto a surface (see Vermeer and Canaletto). The problem was to make that image stay. In the 1820s and 1830s several inventors solved it in different ways.
In France, Louis Daguerre presented his process to the Academy of Sciences on January 7, 1839, and the French government made the details public on August 19, 1839. A daguerreotype is a single, mirror-like image on a silver-coated copper plate; it cannot be copied. In England, William Henry Fox Talbot developed a paper negative from which many positive prints could be made; his improved version, the calotype, was patented in 1841. Talbot's negative-positive idea is the basis of film photography.
Key idea
Looking closely: Boulevard du Temple
Describe. From a high window we look down a long, tree-lined Paris boulevard. The street seems empty, except at the lower left, where a man stands with one foot raised while his boots are polished. Analyze. The exposure took several minutes. Carriages and walkers moved too fast to register and vanished; the man stood still long enough to appear. Interpret. It is often called the first photograph to show a person, by accident. The busy boulevard looks deserted because of the technology, not because it was empty.
Common mistake
Why it works
Photography as art: Julia Margaret Cameron
Julia Margaret Cameron (1815 to 1879) was given a camera in 1863 and took up photography at 48. She made large, close portraits of friends and family with soft focus and strong light from one side, here her niece Julia Jackson in profile. Critics complained about the blur; Cameron chose it, to make portraits that felt like paintings rather than records.
Worked example: Why is the street empty?
- The exposure lasted several minutes.
- Moving carriages and people did not stay in one place long enough to register.
- Only things that stood still, buildings, trees and one man having his boots shined, appear.
Answer: The long exposure erased everything that moved.