Photographic Terms

Aperture
Size of the lens opening through which light passes.

F-Number
Aperture is adjusted in F numbers, being the diameter of the beam of light allowed to pass through the lens, divided into its focal length. The wider the relative aperture the lower the F number. All lenses set to the same F number give images of a distant scene equal brightness.

Shutter
The button that you press to take a picture. On auto focus cameras the shutter button also activates and locks the focus when pressed halfway.

Shutter Speed
The length of time the window in the lens stays open to let light through to the film.

Depth of Field
Distance between nearest and farthest parts of the subject sharply imaged at the same time.

Angle of View
The amount of a scene taken in by a particular lens focal length. Short focal lengths have a wide angle of view, allowing you to photograph a larger portion of the scene then long focal lengths, which have a narrow angle of view.

Film Speed
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