Aplanatic

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Aplanatic \Ap`la*nat"ic\, a. [Gr. 'a priv. + ? disposed to
     wander, wandering, ? to wander.] (Opt.)
     Having two or more parts of different curvatures, so combined
     as to remove spherical aberration; -- said of a lens.
     [1913 Webster]
  


     {Aplanatic focus} of a lens (Opt.), the point or focus from
        which rays diverging pass the lens without spherical
        aberration. In certain forms of lenses there are two such
        foci; and it is by taking advantage of this fact that the
        best aplanatic object glasses of microscopes are
        constructed.
        [1913 Webster]

From WordNet (r) 2.0 [wn]:

  aplanatic
       adj : free from or corrected for spherical aberration; "an
             aplanatic mirror"