Telephoto lens system

Claim 2

A telephoto lens system comprising five lenses, a first lens being a positive meniscus lens with its convex surface positioned on the object side, a second lens being a biconcave lens, a third lens being a positive meniscus lens with its convex surface positioned on the object side, a fourth lens being a negative lens with its concave surface positioned on the object side, and a fifth lens being a biconvex lens, and said telephoto lens system having the following numerical values: r.sub.1 = 0.3186 d.sub.1 = 0.0225 n.sub.1 = 1.48749 ν.sub.1 = 70.1 r.sub.2 = 2.8394 d.sub.2 = 0.0112 r.sub.3 = -0.9987 d.sub.3 = 0.0110 n.sub.2 = 1.7400 ν.sub.2 = 31.7 r.sub.4 = 1.2312 d.sub.4 = 0.0020 r.sub.5 = 0.3283 d.sub.5 = 0.0230 n.sub.3 = 1.52542 ν.sub.3 = 64.5 r.sub.6 = ∞ d.sub.6 = 0.3649 r.sub.7 = -0.1408 d.sub.7 = 0.0100 n.sub.4 = 1.51874 ν.sub.4 = 64.5 r.sub.8 = ∞ d.sub.8 = 0.0140 r.sub.9 = 0.6388 d.sub.9 = 0.0200 n.sub.5 = 1.57309 ν.sub.5 = 42.6 r.sub.10 = -0.4795 f = 1.0 f.sub.B = 0.3413 P = 0.82 1 : 4.5 wherein reference symbol r 1 through r 10 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 9 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 5 respectively represent refractive indexes of respective lenses, reference symbols ν 1 through ν 5 respectively represent Abbe's numbers of respective lenses, reference symbol f represents the focal length of the lens system as a whole, reference symbol f B represents the back focal length, and reference symbol P represents the telephoto ratio.

Claim 3

A telephoto lens system comprising five lenses, a first lens being a positive meniscus lens with its convex surface positioned on the object side, a second lens being a biconcave lens, a third lens being a positive meniscus lens with its convex surface positioned on the object side, a fourth lens being a negative lens with its concave surface positioned on the object side, and a fifth lens being a biconvex lens, and said telephoto lens system having the following numerical values: r.sub.1 = 0.3224 d.sub.1 = 0.0208 n.sub.1 = 1.48749 ν.sub.1 = 70.2 r.sub.2 = 1.3884 d.sub.2 = 0.0105 r.sub.3 = -0.9223 d.sub.3 = 0.0110 n.sub.2 = 1.74000 ν.sub.2 = 28.3 r.sub.4 = 2.6366 d.sub.4 = 0.0020 r.sub.5 = 0.3329 d.sub.5 = 0.0230 n.sub.3 = 1.51821 ν.sub.3 = 65.0 r.sub.6 = ∞ d.sub.6 = 0.3625 r.sub.7 = -0.1406 d.sub.7 = 0.0100 n.sub.4 = 1.49782 ν.sub.4 = 66.8 r.sub.8 = ∞ d.sub.8 = 0.0140 r.sub.9 = 0.7064 d.sub.9 = 0.0250 n.sub.5 = 1.57309 ν.sub.5 = 42.6 r.sub.10 = -0.5568 f = 1.0 f.sub.B = 0.3329 P = 0.81 1 : 4.5 wherein reference symbol r 1 through r 10 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 9 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 5 respectively represent refractive indexes of respective lenses, reference symbols ν 1 through 84 5 respectively represent Abbe's numbers of respective lenses, reference symbol f represents the focal length of the lens system as a whole, reference symbol f B represents the back focal length, and reference symbol P represents the telephoto ratio.

Claim 4

A telephoto lens system comprising five lenses, a first lens being a positive meniscus lens with its convex surface positioned on the object side, a second lens being a biconcave lens, a third lens being a positive meniscus lens with its convex surface positioned on the object side, a fourth lens being a negative lens with its concave surface positioned on the object side, and a fifth lens being a biconvex lens, and said telephoto lens system having the following numerical values: r.sub.1 = 0.3224 d.sub.1 = 0.0208 n.sub.1 = 1.48749 ν.sub.1 = 70.2 r.sub.2 = 1.3884 d.sub.2 = 0.0105 r.sub.3 = -0.9223 d.sub.3 = 0.0110 n.sub.2 = 1.74000 ν.sub.2 = 28.3 r.sub.4 = 2.6366 d.sub.4 = 0.0020 r.sub.5 = 0.3329 d.sub.5 = 0.0230 n.sub.3 = 1.51821 ν.sub.3 = 65.0 r.sub.6 = ∞ d.sub.6 = 0.3625 r.sub.7 = -0.1406 d.sub.7 = 0.0100 n.sub.4 = 1.49782 ν.sub.4 = 66.8 r.sub.8 = ∞ d.sub.8 = 0.0140 r.sub.9 = 0.7064 d.sub.9 = 0.0250 n.sub.5 = 1.57309 ν.sub.5 = 42.6 r.sub.10 = -0.5568 f = 1.0 f.sub.B = 0.3329 P = 0.81 1 : 4.5 wherein reference symbol r 1 through r 10 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 9 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 through n 5 respectively represent refractive indexes of respective lenses, reference symbols ν 1 through 84 5 respectively represent Abbe's numbers of respective lenses, reference symbol f represents the focal length of the lens system as a whole, reference symbol f B represents the back focal length, and reference symbol P represents the telephoto ratio.