focal length
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
1745–55
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2013.
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Based on the Random House Dictionary, © Random House, Inc. 2013.
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Link To focal length
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
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2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
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00:10
Focal length
is always a great word to know.
So is ninnyhammer. Does it mean:
| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |
| a fool or simpleton; ninny. |
American Heritage
Medical Dictionary
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.
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Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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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.
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Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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American Heritage
The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
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