Word Study
[2x]
: Pâ Pæ Pè Pé Pœ P- P. P/ P< Pa Pb Pc Pd Pe Pf Ph Pi Pj Pk Pl Pm Pn Po Pp Pr Ps Pt Pu Pv Pw Px Py
parfocal
CIDE DICTIONARY
parfocal, a. [Pari- + focal.].
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. [Webster 1913 Suppl.]
For further exploring for "parfocal" in Webster Dictionary Online
