FAST LENS Russian patent published in 2000 - IPC

FIELD: optical instrumentation engineering; precision viewing devices. SUBSTANCE: fast lens has first, second, third, fourth, and fifth components which are negative meniscus facing image with its concave side, bi-convex lens, bi-concave lens, plano-convex lens, and bi-convex lens, respectively. Focal distances of lens and its components, thicknesses of components, air gaps, curvature radii, and refractive indices of components are interrelated by definite dependences. Fast lens has relative aperture at least 1:1.7, angular field in space of objects over 47 deg at high quality of dot image on axis and over field. EFFECT: improved characteristics of lens. 3 dwg