f-number

f-num·ber

(ĕf′nŭm′bər)

n.

The ratio of the focal length of a lens or lens system to the effective diameter of its aperture. Also called f-stop.

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[f(ocal length) + number.]

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

f-number

or

f number

n

(Photography) photog the numerical value of the relative aperture. If the relative aperture is f8, 8 is the f-number and indicates that the focal length of the lens is 8 times the size of the lens aperture. See also T-number

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

f-number

(ˈɛfˌnʌm bər)

n.

a number corresponding to the ratio of the focal length to the diameter of a lens system, esp. a camera lens. Symbol: f/

[1890–95]

Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

Translations

f-number

n (Phot) → Blende f, → Blendenzahl f

Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007