In 1826, a Frenchman named Niepce needed pictures for his business. But he was not a good artist. So he invented a very simple camera. He put it in a window of his house and took a picture of his yard. That was the first photograph. The next important date in the history of photography was 1837. That year, Daguerre, another French, took a picture of his studio. He used a new kind of camera and a different process. In his pictures, you could see everything very clearly, even the smallest details. This kind of photograph was called a Daguerreotype (银板照相法). Soon, other people began to use Daguerre's process. Travelers brought back daguerreotypes from all around the world. People photographed famous buildings, cities and mountains. In about 1840, the process was improved. Then photographers could take pictures of people and moving things. The process was not simple. Tile photographers had to carry lots of films and processing equipment. But this did not stop the photographers, especially in the United States. After the 1840s daguerreotype artists were popular in most cities. Mathew Brady was a well-known American photographer. He took many pictures of famous people. The pictures were unusual because they were very life-like and full of personality (个性). Brady was also the first person to take pictures of war. His 1862 Civil War pictures showed dead soldiers and mined cities. They made the war seem more real and more terrible. In the 1880s, new inventions began to change photography... Photographers could buy films ready made in roils (卷). So they did not have to make the film themselves. Also, they did not have to process the film immediately. They could bring it back to their studios and develop it later, !which means that they did not have to carry lots of equipment. And finally, the invention of the small handheld camera made photography less expensive. With the small camera, anyone could be a photographer. People began to use cameras just for fun. They took pictures of their families, friends and favorite places. They called these pictures 'snapshot'. Photographs became very popular in newspapers in the 1890s. Soon magazines and books also used documentary photographs. These pictures showed true events and people. They were much more real than drawing. Photography also turned into a form. of art by the end of the 19th century. Some photographs were not just copies of the real world. They showed ideas and feelings, like other art forms. The passage is mainly about______.