Parfocal
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. ``the convenience of a microscope with parfocal objective lenses'' [Webster 1913 Suppl.]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • parfocal — Microscope objectives that are mounted in such a way that changing objectives does not put the specimen out of focus are parfocal …   Dictionary of molecular biology

  • parfocal — 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 …   New Collegiate Dictionary

  • parfocal — (par fo kal) A microscope that retains proper focus when the objectives are changed …   Dictionary of microbiology

  • parfocal — /pahr foh keuhl/, adj. Optics. of or pertaining to different eyepieces (of telescopes or microscopes) that all focus their images in the same plane, so that they can be interchanged without readjusting the instrument. [1885 90; PAR1 + FOCAL] * *… …   Universalium

  • parfocal — adjective Having multiple lenses that have corresponding focal points in the same plane …   Wiktionary

  • parfocal — par·fo·cal ( )pär fō kəl adj having corresponding focal points all in the same plane: having sets of objectives or eyepieces so mounted that they may be interchanged without varying the focus of the instrument (as a microscope) with which they… …   Medical dictionary

  • parfocal — par·focal …   English syllables

  • parfocal — (ˈ)pär+ adjective Etymology: Latin par equal + English focal more at pair : having corresponding focal points all in the same plane : having sets of objectives or eyepieces so mounted that they may be interchanged without varying the focus of the …   Useful english dictionary

  • Parfocal lens — A parfocal lens is a lens that stays in focus when magnification/focal length is changed. There is inevitably some amount of focus error, but small enough not to be considered significant.MicroscopyParfocal microscope objectives stay in focus… …   Wikipedia

  • Zoom lens — Nikkor 28 200 mm zoom lens, extended to 200 mm at left and collapsed to 28 mm focal length at right A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a fixed… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”