Seven-element rapid photographic lens

摘要

The invention relates to a seven-element rapid photographic lens of the double Gausian type for single-lens reflex cameras, having a relative aperture of 1:1.4, an angular field of 2 sigma = 46 DEG and an image-side intersection length (S') of at least 0.72 times the focal length. The object-side lens part consists of two converging meniscuses and one diverging meniscus, and the image-side lens part consists of a cemented diverging meniscus, a downstream converging meniscus and a converging lens. Features of the invention are that use is made of glasses which have a lower refractive index and are therefore cost effective, that the first lens is relatively spherical, and that the second air space has the form of a thin diverging meniscus.