focal distance

focal length

noun Optics.
1.
the distance from a focal point of a lens or mirror to the corresponding principal plane. Symbol: f
2.
the distance between an object lens and its corresponding focal plane in a telescope.
Also called focal distance.


Origin:
1745–55

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To focal distance
Collins
World English Dictionary
focal length or focal distance
 
n
the distance from the focal point of a lens or mirror to the reflecting surface of the mirror or the centre point of the lens
 
focal distance or focal distance
 
n

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
American Heritage
Medical Dictionary

focal distance n.
See focal length.

focal length n.
The distance from the surface of a lens or mirror to its focal point. Also called focal distance, focus.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
focal length   (fō'kəl)  Pronunciation Key 
The distance between the optical center of a lens or mirror to its focal point.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
American Heritage
Cultural Dictionary

focal length definition


The distance between the focal point of a lens (that is, the point at which the lens will focus parallel rays of light) and the lens itself.

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature