How a camera works

The simple camera is similar is in principle to the human eye. The camera is used in taking photographs of an object or a view. It is made up of a light proof box with a converging lens in front and and a light sensitive film at the back. A provision is made for adjusting the distance between the lens and the film, so objects in front of the lens can always be focused on the film by the converging lens. A better image can be formed by replacing the converging lens by different lenses.
A shutter of variable speed between the lens and the film shutts off light from the film and a diaphragm regulates the size of an aperture which controls the amount of light energy going into the film.
In taking a photograph, the camera is pointed at the object and the focusing ring is used to adjust the distance of the lens from the film until a sharp image is formed on the film. When a button is pressed, the shutter quickly opens and closes, exposing the film, for a brief period to light from the object. After the photograph is taken, the film is wound in between the spools.