Term - F/number
|F/number||SWPP and BPPA Photographic Glossary|
Friday 24th May 2013
The lens focal length divided by effective diameter of the aperture gives the f/number that's used to indicate the aperture value. Each full f/number halves or doubles image brightness and some lenses can also be controlled in half or third stop steps.
Information provided by: SWPP BPPA
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