1839, Daguerre made the first practical silver camera. The basic idea is to expose a copper plate coated with silver iodide, then steam it with mercury vapor and fix it with ordinary salt solution to form a permanent image.

Later, Daguerre made the world's first camera in this way. At the same time, Daguerre photography is the first successful photography method in the world.

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As early as 1822, Daguerre opened an exhibition in Paris, called the peep show, which caused a sensation at that time. This is a kind of landscape exhibition that produces various effects through the change of lighting, which is somewhat similar to today's slide show technology, and it is also Daguerre's initial exploration of photography.

Later, Daguerre invented Daguerre technology on the basis of previous research results. He first dipped the silver-plated copper plate in iodine to get silver iodide, and then exposed it for a few minutes. Then he heated the mercury to 75 degrees Celsius to fumigate the silver plate, so that the silver and mercury were homogenized, thus producing an image. Finally he cured it with salt water.

These steps make up Daguerre Photography. The obtained plate leaves a general image exactly the same as the original scene in the mirror. Images must be viewed from one angle and sealed to prevent fingerprints, so they are usually packed in boxes with glass in front. For the public, it shows the mysterious big box at the scene, the unpleasant smell of chemical reaction and the toxicity of mercury vapor.

All these give photography a magical color. Compared with previous photography, the exposure time of Daguerre photography only takes more than ten minutes, and the image is clearer. Because the exposure time still takes more than ten minutes, when taking portraits at that time, a neck frame was needed to support the head and keep people still.

On August 1839 and 19, the French Academy of Science and Art purchased its patent on photography, and announced this revolutionary invention to the world, announcing the birth of photography. The French government announced that this invention was a gift to the freedom of the world. ? This day is also designated as the birth day of photography.

Baidu Encyclopedia-Daguerre