Adjacent Words

parfocal definitions

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Merriam Webster's

adjective Etymology: Latin par equal + English focal Date: circa 1886 being or having lenses or lens sets (as eyepieces) with the corresponding focal points all in the same plane • parfocality noun • parfocalize transitive verb

Webster's 1913 Dictionary

Parfocal Par*fo"cal, a. [Pari- + focal.] (Opt.) With the lower focal points all in the same plane; -- said of sets of eyepieces so mounted that they may be interchanged without varying the focus of the instrument (as a microscope or telescope) with which they are used.