Photographic lens system

Claim 2

A photographic lens system comprising a first lens component of a meniscus positive lens with its convex surface on the object side, a second lens component of a biconcave lens, a third lens component of a biconvex lens and a fourth lens component of a meniscus negative lens with its convex surface on the image side, the said lens system satisfying the following conditions: 1.5<f/f.sub.123 <1.7 (1) -1.3<f/f.sub.4 <-1.0 (2) 0.07<d.sub.5 f<0.11 (3) 0.14<d.sub.6 /f<0.19 (4) wherein the reference symbol f represents the focal length of the total lens system, the symbol f 123 represents the composite focal length of the first, second and third lens components, the symbol f 4 represents the focal length of the fourth lens component, the symbol d 5 represents the axial thickness of the third lens component and the symbol d 6 represents the axial air space between the third and fourth lens components, respectively.

Claim 3

A photographic lens system according to claim 1, having the following data: ______________________________________ r.sub.1 = 28.05 d.sub.1 = 9.12 n.sub.1 = 1.72 ν.sub.1 = 50.25 r.sub.2 = 77.488 d.sub.2 = 2.65 r.sub.3 = -147.238 d.sub.3 = 2.94 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 45.879 d.sub.4 = 5.57 r.sub.5 = 58.624 d.sub.5 = 10.56 n.sub.3 = 1.70154 ν.sub.3 = 41.10 r.sub.6 = -77.882 d.sub.6 = 16.49 r.sub.7 = -20.018 d.sub.7 = 3.82 n.sub.4 = 1.78590 ν.sub.4 = 44.18 r.sub.8 = -29.550 f = 100 f/f.sub.123 = 1.590 f/f.sub.4 = -1.043 d.sub.5 /f = 0.106 d.sub.6 /f = 0.165 |r.sub.7 |/f = 0.2 ______________________________________ wherein the reference symbols r 1 through r 8 represent radii of curvature of the respective lens surfaces, the symbols d 1 through d 7 represent the axial thicknesses of the respective lenses and axial air spaces between the lenses, the symbols n 1 through n 4 represent the refractive indices of the respective lenses, the symbols ν 1 through ν 4 represent the Abbe numbers of the respective lenses, the symbol f represents the focal length of the total lens system, the symbol f 123 represents the composite focal length of the first, second and third lens components and the symbol f 4 represents the focal length of the fourth lens component, respectively.

Claim 4

A photographic lens system according to claim 1, having the following data: ______________________________________ r.sub.1 = 26.309 d.sub.1 = 5.97 n.sub.1 = 1.72 ν.sub.1 = 46.03 r.sub.2 = 67.844 d.sub.2 = 1.91 r.sub.3 = -146.694 d.sub.3 = 2.94 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 46.450 d.sub.4 = 4.71 r.sub.5 = 59.753 d.sub.5 = 10.38 n.sub.3 = 1.70154 ν.sub.3 = 41.1 r.sub.6 = -77.156 d.sub.6 = 18.76 r.sub.7 = -18.674 d.sub.7 = 3.82 n.sub.4 = 1.78590 ν.sub.4 = 44.18 r.sub.8 = -26.841 f = 100 f/f.sub.123 = 1.61 f/f.sub.4 = -1.017 d.sub.5 /f = 0.104 d.sub.6 /f = 0.188 |r.sub.7 |/f = 0.187 ______________________________________ wherein the reference symbols r 1 through r 8 represent radii of curvature of the respective lens surfaces, the symbols d 1 through d 7 represent the axial thicknesses of the respective lenses and axial air spaces between the lenses, the symbols n 1 through n 4 represent the refractive indices of the respective lenses, the symbols ν 1 through ν 4 represent the Abbe numbers of the respective lenses, the symbol f represents the focal length of the total lens system, the symbol f 123 represents the composite focal length of the first, second and third lens components and the symbol f 4 represents the focal length of the fourth lens component, respectively.

Claim 5

A photographic lens system according to claim 1, having the following data: ______________________________________ r.sub.1 = 29.696 d.sub.1 = 9.41 n.sub.1 = 1.6935 ν.sub.1 = 53.23 r.sub.2 = 80.265 d.sub.2 = 3.22 r.sub.3 = -135.051 d.sub.3 = 2.95 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 73.938 d.sub.4 = 8.58 r.sub.5 = 56.077 d.sub.5 = 7.39 n.sub.3 = 1.62280 ν.sub.3 = 57.06 r.sub.6 = -88.905 d.sub.6 = 17.02 r.sub.7 = -19.867 d.sub.7 = 4.09 n.sub.4 = 1.691 ν.sub.4 = 54.84 r.sub.8 = -33.215 f = 100 f/f.sub.123 = 1.63 f/f.sub.4 = -1.222 d.sub.5 /f = 0.074 d.sub.6 /f = 0.170 |r.sub.7 |/f = 0.199 ______________________________________ wherein the reference symbols r 1 through r 8 represent radii of curvature of the respective lens surfaces, the symbols d 1 through d 7 represent the axial thicknesses of the respective lenses and axial air spaces between the lenses, the symbols n 1 through n 4 represent the refractive indices of the respective lenses, the symbols ν 1 through ν 4 represent the Abbe numbers of the respective lenses, the symbol f represents the focal length of the total lens system, the symbol f 123 represents the composite focal length of the first, second and third lens components and the symbol f 4 represents the focal length of the fourth lens component, respectively.

Claim 6

A photographic lens system according to claim 1, having the following data: ______________________________________ r.sub.1 = 28.975 d.sub.1 = 9.66 n.sub.1 = 1.69100 ν.sub.1 = 54.84 r.sub.2 = 80.927 d.sub.2 = 3.07 r.sub.3 = -132.851 d.sub.3 = 2.96 n.sub.2 = 1.74077 ν.sub.2 = 27.79 r.sub.4 = 58.815 d.sub.4 = 8.03 r.sub.5 = 54.074 d.sub.5 = 7.68 n.sub.3 = 1.60311 ν.sub.3 = 60.70 r.sub.6 = -79.364 d.sub.6 = 16.01 r.sub.7 = -19.696 d.sub.7 = 3.24 n.sub.4 = 1.69100 ν.sub.4 = 54.84 r.sub.8 = -31.503 f = 100 f/f.sub.123 = 1.61 f/f.sub.4 = -1.167 d.sub.5 /f = 0.077 d.sub.6 /f = 0.160 |r.sub.7 |/f = 0.197 ______________________________________ wherein the reference symbols r 1 through r 8 represent radii of curvature of the respective lens surfaces, the symbols d 1 through d 7 represent the axial thicknesses of the respective lenses and axial air spaces between the lenses, the symbols n 1 through n 4 represent the refractive indices of the respective lenses, the symbols ν 1 through ν 4 represent the Abbe numbers of the respective lenses, the symbol f represents the focal length of the total lens system, the symbol f 123 represents the composite focal length of the first, second and third lens components and the symbol f 4 represents the focal length of the fourth lens component, respectively.

Claim 7

A photographic lens system according to claim 1, having the following data: ______________________________________ r.sub.1 = 28.109 d.sub.1 = 10.29 n.sub.1 = 1.691 ν.sub.1 = 54.84 r.sub.2 = 92.061 d.sub.2 = 2.35 r.sub.3 = -196.173 d.sub.3 = 2.94 n.sub.2 = 1.78472 ν.sub.2 = 25.71 r.sub.4 = 52.777 d.sub.4 = 7.59 r.sub.5 = 60.411 d.sub.5 = 8.54 n.sub.3 = 1.60342 ν.sub.3 = 38.01 r.sub.6 = -80.771 d.sub.6 = 14.07 r.sub.7 = -19.490 d.sub.7 = 4.53 n.sub.4 = 1.744 ν.sub.4 = 44.73 r.sub.8 = -29.810 f = 100 f/f.sub.123 = 1.613 f/f.sub.4 = -1.074 d.sub.5 /f = 0.085 d.sub.6 /f = 0.141 |r.sub.7 |/f = 0.195 ______________________________________ wherein the reference symbols r 1 through r 8 represent radii of curvature of the respective lens surfaces, the symbols d 1 through d 7 represent the axial thicknesses of the respective lenses and axial air spaces between the lenses, the symbols n 1 through n 4 represent the refractive indices of the respective lenses, the symbols ν 1 through ν 4 represent the Abbe numbers of the respective lenses, the symbol f represents the focal length of the total lens system, the symbol f 123 represents the composite focal length of the first, second and third lens components and the symbol f 4 represents the focal length of the fourth lens component, respectively.