Today I'll talk about the invention of the camera and photography (摄影). The camera is often thought to be a modem invention, but as early as 1727, a German physicist discovered that light darkens silver salt. Used as a camera, a big box was set up, and a small hole was cut in one side to let the light in. he made temporary pictures on the silver salt. Silver salt is still the base of the photographic film today. Then a French scientist named Joseph made the first permanent (永久的) picture by using a special piece of metal which was covered with silver salt. A photo he made in 1826 still exists.
The painter De Gear improved the method by covering the metal also with placing the common salt which we can eat. This was in 1839, the official date of the beginning of photography. But the problem was the printing of the photos. And it wasn't until other scientists developed the kind of photographic paper that good prints were possible and photography became truly modem. In the 1870s, Matthew Bradey was able to take his famous pictures in American Civil War. In the 20s of this century, Dr Edward Lane invented the so-called "Instant Camera" which uses self-developing film. If we say photography came into being in 1839, it follows that it took more than 100 years for the camera to reach its present condition.
