Question
Describe the action of a camera.
Answer
A photographic camera uses a convex lens of short focal length to capture a permanent image of an object on a light-sensitive film or photographic plate. The film is coated with silver halide, and when light falls on it, a chemical reaction occurs. Different amounts of light from various parts of the object affect different areas of the film, resulting in a negative image. The film is then chemically developed, and a positive print of the picture is obtained.
