back focus


Definition of back focus

: the distance from the rear glass surface of a photographic lens to the focal plane when the lens is focused on a very distant object

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First Known Use of back focus

1868, in the meaning defined above

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The first known use of back focus was in 1868

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Cite this Entry

“Back focus.” Dictionary, Merriam-Webster, Accessed 27 Jan. 2021.

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