Dictionary.com

relative aperture

noun Optics.

the ratio of the diameter of a lens, especially a camera lens, to the focal length; the reciprocal of the f number or focal ratio of the lens.

QUIZZES

CAN YOU GUESS THESE WORDS FROM AROUND THE US?

American English is not always as it appears to be ... get to know regional words in this quiz!
Question 1 of 10
A bet is synonymous with a wager, but what does it mean in New York?
Often it means something is impossible.
It’s another way to agree with someone.
It serves as an apology.
TAKE THE QUIZ TO FIND OUT
Also called aperture ratio .

Origin of relative aperture

First recorded in 1885–90

Words nearby relative aperture

relations, relationship, relationship marketing, relative, relative accommodation, relative aperture, relative atomic mass, relative bearing, relative clause, relative complement, relative density
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for relative aperture

relative aperture

noun

photog the ratio of the equivalent focal length of a lens to the effective aperture of the lens; written as f/n, f:n, or fn, where n is the numerical value of this ratio and is equivalent to the f-number
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012