Having several elements of different curvatures so combined regarding pull spherical aberration said of a lens
- free from or fixed for spherical aberration
- Having a couple of elements of different curvatures, so combined on eliminate spherical aberration; -- said of a lens.
(a.) Having a couple of areas of various curvatures, so combined as to eliminate spherical aberration; -- said of a lens.
According to Abbe, a system can only be regarded as aplanatic if it is spherically corrected for not only one axial point, but when it also fulfils the sine-condition and thus magnifies equally in all zones a surface-element situated vertically on the axis at this point.