actinic focus


Definition of actinic focus

: the focus at which the chemically most effective rays as distinguished from the visually most effective are brought together (as by a lens)

called also chemical focus

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First Known Use of actinic focus

1853, in the meaning defined above

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The first known use of actinic focus was in 1853

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Cite this Entry

“Actinic focus.” Dictionary, Merriam-Webster, Accessed 6 Mar. 2021.

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