Principal point
Principal Prin"ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a state; the principal productions of a country; the principal arguments in a case. [1913 Webster]

Wisdom is the principal thing. --Prov. iv. 7. [1913 Webster]

2. Of or pertaining to a prince; princely. [A Latinism] [Obs.] --Spenser. [1913 Webster]

{Principal axis}. See {Axis of a curve}, under {Axis}.

{Principal axes of a quadric} (Geom.), three lines in which the principal planes of the solid intersect two and two, as in an ellipsoid.

{Principal challenge}. (Law) See under {Challenge}.

{Principal plane}. See {Plane of projection} (a), under {Plane}.

{Principal of a quadric} (Geom.), three planes each of which is at right angles to the other two, and bisects all chords of the quadric perpendicular to the plane, as in an ellipsoid.

{Principal point} (Persp.), the projection of the point of sight upon the plane of projection.

{Principal ray} (Persp.), the line drawn through the point of sight perpendicular to the perspective plane.

{Principal section} (Crystallog.), a plane passing through the optical axis of a crystal. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • principal point — n either of two points on the principal axis of a lens where the object and image have the same size and are not inverted in relation to each other …   Medical dictionary

  • principal point — index gist (ground for a suit), main point Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • Principal Point — (coord|64|55|S|63|27|W|) is a prominent ice covered headland lying 4 nautical miles (7 km) east of Cape Errera and forming the southeast end of Wiencke Island, in the Palmer Archipelago. First charted by the French Antarctic Expedition under… …   Wikipedia

  • principal point — noun 1. : the point at which a principal visual ray intersects a perspective plane 2. : either of two points on the axis of a lens so related that a ray from any point of the object directed toward one principal point will emerge from the lens in …   Useful english dictionary

  • principal point — pagrindinis taškas statusas T sritis fizika atitikmenys: angl. principal point vok. Hauptpunkt, m rus. главная точка, f pranc. point principal, m …   Fizikos terminų žodynas

  • principal point — pagrindinis taškas statusas T sritis Gynyba apibrėžtis Fotogrametrijoje – taškas pagrindo plokštumoje, kurioje tiesė, einanti per perspektyvinį centrą, yra statmena fotografijos plokštumai ir kerta pagrindo plokštumą. atitikmenys: angl. principal …   NATO terminų aiškinamasis žodynas

  • principal point — Optics. the point where a principal plane intersects the axis. [1695 1705] * * * …   Universalium

  • principal point — As it relates to photography, it is the foot of the perpendicular to the photo plane through the perspective center. Generally, it is determined by the intersection of the lines joining opposite or diagonal collimating or fiducial marks. See also …   Aviation dictionary

  • principal point of lens — pagrindinis lęšio taškas statusas T sritis fizika atitikmenys: angl. principal point of lens vok. Hauptpunkt der Linse, m rus. главная точка линзы, f pranc. point principal de la lentille, m …   Fizikos terminų žodynas

  • principal — Principal, Estre le Principal et plus excellent, Primas partes in re aliqua agere, Principatum tenere. Pansa a esté nostre principal aide et secours, Principem habuimus Pansam. Laquelle chose est la principale et la meilleure, et la plus forte,… …   Thresor de la langue françoyse

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