The Collaborative International Dictionary of English. 2000.
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 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
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
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
