Wide-angle objective

摘要

A wide-angle objective composed of six components separated by air spaces and located three at the object side and three at the image side of a diaphragm, said six lens components taken in consecutive order from the side of the object comprising: a first lens component with dispersing refractive power; a second lens component which follows an air space composed of a dispersing meniscus lens component curved towards the object side; a third lens component which follows a small air space and possessing a collecting refractive power and having a strongly convex curved outer surface facing the object side; a fourth lens component which follows the diaphragm space, said fourth lens component having a collecting refractive power; a fifth lens component comprising a meniscus lens component which is curved towards the image and assembled preferably from at least one dispersing and collecting lens; a sixth lens component with dispersing power which follows an air space and composed of at least one meniscus lens member curved towards the image; the difference of the reciprocal values of the radii of curvature of the lens surfaces bounding the diaphragm space is greater than 0.43/F and smaller than 1.3/F; and the axial spacing of the convex surfaces of the second and fifth lens components facing away from the diaphragm being in the order of between 0.58 F and 1.25 F and the focal length of the first lens component facing towards the object is greater than -0.7 F and smaller than -1.6 F.