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back focus

noun

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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Dictionary Entries near back focus

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backflip

backflow

back focus

back-formation

back forty

backfriend

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Time Traveler for back focus

The first known use of back focus was in 1868

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