aperture

The aperture of a lens system is the opening between the actual lens elements, typically made of glass or plastic, and the camera's digital sensor that translates the light into image data. Aperture openings are referred to in terms of stops or f-stops that equate to the ratio of the lens focal length to the diameter of the opening. A lens system with a focal length of 50mm and an aperture opening that is 25mm in diameter would equate to an f-stop of 2, and would be known as a 50mm f2 lens. Some lenses have variable apertures that can be set to one of multiple f-stop values. Reducing the aperture size decreases the amount of light that makes it to the sensor as well as increases the amount of depth of field that the lens will provide.
Also known as: "f-number", "f-stop"

AMPS
A-GPS

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