relative aperture

noun

: a measure of the angle of the cone of light rays from an object that traverse an optical system
specifically : the effective aperture of a camera lens expressed as a fraction of its focal length with the symbol f being used instead of 1 as the numerator or expressed as the ratio of the effective aperture to the focal length
a lens having an effective aperture that is 1/45 of its focal length has a relative aperture of f/4.5 or 1:4.5

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near relative aperture

Cite this Entry

“Relative aperture.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/relative%20aperture. Accessed 29 Nov. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!