focal length

noun
|Updated on: 25 Jul 2018

Definition of focal length

: the distance of a focus from the surface of a lens or curved mirror

Recent Examples of focal length from the Web

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First Known Use of focal length

1682

in the meaning defined above

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FOCAL LENGTH Defined for English Language Learners

focal length

Definition of focal length for English Language Learners

  • : the distance from the surface of a lens to the point of focus (sense 3)


Medical Dictionary

focal length

noun \ -ˌleŋ(k)th \

medical Definition of focal length

: the distance of a focus from the surface of a lens or concave mirror symbol f

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