| Camera, a device used in photography. All | | | | f-number. |
| cameras have four fundamental parts: The body, | | | | The Shutter, it is usually mounted behind the lens |
| a light-tight box that serves as a rigid framework | | | | or between the elements of a complex lens. |
| on which all other parts are mounted and also | | | | Shutter that are mounted lens elements are called |
| serve to protect the film from exposure to light, | | | | between-the-lens shutter while those mounted |
| except in the process of taking the photograph. | | | | immediately in front of the film are called |
| The body is mostly composed of hard plastic and | | | | focal-plane shutter. Most shutter incorporate a |
| light metal. | | | | timing mechanism that makes it possible to vary |
| Next is the lens, which is the one responsible for | | | | the length of an exposure. When set at a high |
| gathering image. It is mounted in front of the | | | | speed such as 1/500 of a second, the shutter |
| camera body focusing the rays of the light from | | | | admits relatively little light. For a low speed of 1/5 |
| the object. In some camera lens, it is in a form of | | | | of a second, the shutter is open 100 times as |
| a plastic or glass and in more elaborate camera, | | | | long and admits about 100 times as much light. |
| its lens is consist of several piece of glass | | | | High shutter speed are particularly useful for |
| mounted in a cylinder called the lens barrel. The | | | | producing picture of sharp moving objects. |
| lens has its light gathering power and it is indicated | | | | And finally the Film Holder. It holds the film in place |
| by the f-numbers or relative aperture, which is | | | | at the back of the camera. It is design to hold the |
| usually marked on the lens barrel. Lenses with low | | | | film flat so that the image produced by the lens |
| f-numbers have relatively high light-gathering | | | | will be sharp over the whole picture area. In most |
| power and are called the fast lenses, while lens | | | | roll-film cameras the film compartment is place in |
| with high f-numbers have low light-gathering | | | | to the back of the camera and a spring mounted |
| power and called the slow lenses. | | | | pressure plate place in the back cover of the |
| The light-gathering power of most camera lenses | | | | camera this pressure plate keeps the film flat |
| are controlled by means of a diaphragm. In many | | | | across the picture area opening. |
| cameras the amount of light that's strikes the film | | | | In its history, the photographic camera was |
| can be controlled by opening or closing the | | | | developed from the camera obscura, a device |
| diaphragm. The diaphragm resembles the iris of an | | | | describe earlier than 1039 by the Arabian Scholar |
| eye. When the diaphragm is widely open, it allows | | | | Alhazen. It consisted of a darkened room with a |
| a maximum light to pass into it. When partially | | | | hole in one wall which light coming from the scene |
| closed, it reduces the amount of light that pass | | | | outside formed an image on the opposite wall. For |
| into it. Since closing the diaphragm reduces the | | | | centuries however, there was no method of |
| light-gathering power of the lens, it has the effect | | | | recording the image produced, other than drawing |
| of slowing the lens and thus increasing its | | | | it. |