A camera helps us in taking the picture of a person or scene, which is called photograph. So, the camera forms the most vital mode of communication and expression in modern times. It is commonly known to all that a camera takes photographs. But, it is very interesting to know how does a camera take a photograph.
Basically, a camera is a dark box containing a lens on one side. Just behind the lens there is an aperture that manages the amount of light coming in. A shutter exposes the film to the light for a short time duration. A photosensitive film having a coating of silver bromide is mounted on the other side of the lens.
The person or thing, whose photograph is to be clicked, is focused on the film. This is done with the aid of another lens known as view finder. When the shutter is opened the light from the object comes in the box through the lens. An inverted image of the object is taken on the photo film.
The expose film is taken out of the camera and is develop by a chemical process in the photograph developing laboratory. A solution of quinol and metal is employed for developing the film. In this process the part on which more light has fallen becomes darker on the image of the item comes out in reverse tones. The developed film is immersed in the hypo solution for fixing the image. That is how the negative of the object is obtained. In the negative white portions seem dark while black portions seen white.
Then, from the negative with the add of an enlarger, a print or positive is made. The light coming through the negative is constructed on the photosensitive bromide paper. This paper after developing and fixing, becomes the of positive. That is how the photograph of an object is obtained.