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Definitions from WordNet

Definitions from the Web

Noun

Definition: In photography, the f number refers to the numerical value of the aperture (opening) of a camera lens. It determines the amount of light that enters the camera and affects the depth of field.

Example sentence: The photographer adjusted the f number to capture a shallow depth of field, focusing on the flower in the foreground while blurring the background.

Noun

Definition: In optics, the f number represents the ratio of the focal length of a lens to the diameter of its aperture. It determines the light-gathering ability and performance of lenses in various optical systems.

Example sentence: This telescope has a high f number, indicating a longer focal length and narrower field of view, ideal for observing distant celestial objects.

Noun

Definition: In the field of radiography, the f number refers to the speed class of dental X-ray film. It indicates the film's sensitivity to X-rays and its ability to produce clear and well-defined images.

Example sentence: The dentist used a dental X-ray film with a high f number to capture detailed images of the patient's teeth and detect any hidden cavities.

Noun

Definition: In mathematics, the f number refers to a specific number used as an index in various equations and formulas.

Example sentence: The formula for calculating the area of a circle involves using the value of π, a transcendental f number with an approximate value of 3.14159.