Anamorphic objective zoom lens

Abstract

The anamorphic objective zoom lens includes, along an optical axis and in order from an object space to an image space: at least a negative (−) power spherical first lens group; an anamorphic second lens group, spherical third lens group preferably having positive (+) power, a variable power spherical fourth lens group and a positive (+) power spherical fifth lens group. The aperture stop is located before, after or preferably within the spherical fifth lens group. All spherical lens groups contain spherical and piano refractive optical surfaces. The anamorphic second lens group contains cylindrical and plano optical surfaces with at least one cylindrical surface oriented at substantially 90 degrees about at least one other cylindrical surface. The spherical first lens group may provide focusing. The variable power spherical fourth lens group provides zooming. The spherical third and fifth lens groups may provide compensation for thermal defocus.

Dependencies are inferred from the claim text.