Fast gauss projection lens - uses standard glass with relative aperture above one to one point two

摘要

The lens comprises a simple planoconvex element (I), a positive meniscus (II) and a negative meniscus (III) with their refractive surfaces facing the film plane (A), a negative element IV with its refractive surface facing away from the film plane, a fifth element (V) comprising a negative meniscus (Va) with its refractive surfaces facing the film plane cemented to a biconvex member (Vb) and a positive meniscus (VI) with its refractive surfaces facing the film plane. The lens design and type of glass used are such that the Petzval sum does not exceed 0.35. Perfect correction is thus achieved for 16mm projection.