Having numerous lenses that have matching things in the same airplane
aided by the lower things all in similar airplane; -- stated of sets of eyepieces therefore mounted they is interchanged without varying the main focus of the instrument (as a microscope or telescope) with that they are utilized.
Using The lower points of interest all-in the exact same jet: said of interchangeable eyepieces, for microscopes or telescopes, therefore mounted that whichever a person is used the focus remains the exact same. See eyepiece.
Definition for "parfocal"
Having numerous lenses that have matching things in…