The Camera


Definitions :

Aperture - is a hole or an opening through which light is admitted.

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Shutter - is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene.

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Exposure - is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph.

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Depth of field - is the portion of a scene that appears sharp in the image.

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F-stop - expresses the diameter of the entrance pupil in terms of the focal length of the lens; in simpler terms, the f-number is the focal length divided by the "effective" aperture diameter.

Focal length - is a measure of how strongly it converges (focuses) or diverges (diffuses) light.

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My words :

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Focusing Screen- A camera in which the image appears on a ground-glass. The lenses being mechanically coupled for focusing.

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Pentaprism- A prism that has five faces, a pair of which are at 90 degress to each other, a ray entering one of the pair emerges from the other at an angle of 90 degress to its original direction: used esp. in single-lens reflex cameras to reverse images laterally and reflect them to the viewfinder.

Pixel- The smallest element of an image that can be individually processed in a video display system.

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Autofocus- Automatically having to focus the lens of an image.