Large-aperture macro lens system

Claim 2

A large-aperture macro lens systems comprising a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power in the order from the object side, said large-aperture macro lens system being arranged that, when focusing from an infinite distance object to a short distance object is performed, the airspace between said first and second lens groups is varied in a pattern that said airspace is increased and, then, decreased by changing the varying direction near the position of the intermediate photographing magnification.

Claim 3

A large-aperture macro lens system according to claim 1 arranged that, when focusing from an infinite distance object to a short distance object is performed the airspace between said second and third lens groups is increased continuously.

Claim 4

A large-aperture macro lens system according to claim 2 wherein said first lens group comprises at least one negative lens, said large-aperture macro lens system being arranged to fulfill the following conditions: (1) 1.7<|f.sub.3 |/f<10, f.sub.3 <0 (1) (2) 0>ΔD.sub.1 <2 (2) (3) ν.sub.1.sbsb.n <50 (3) (4) n.sub.3.sbsb.n <1.65 (4) where, reference symbol f represents the focal length of the lens system as a whole, reference symbol f 3 represents the focal length of the third lens group, reference symbol ΔD 1 represents the difference between the largest value of the airspace between the first and second lens groups and value of said airspace when focused on an object at a distance corresponding to the photographing magnification of 1×, reference symbol ν 1 .sbsb.n represents Abbe's number of the negative lens comprised in the first lens group, and reference symbol n 3 .sbsb.n represents the refractive index of the negative lens comprised in the third lens group.

Claim 5

A large-aperture macro lens system according to claim 3 further fulfilling the condition (5) shown below: 0.5<|ra|/f-1.0 (5) where, reference symbol r a represents the radius of curvature of the surface having the strongest diverging action out of respective surfaces in the third lens group.

Claim 6

A large-aperture macro lens system according to claim 3 wherein said first lens group comprises at least first and second lens components, further fulfilling the condition (6) shown below: 1.7<n.sub.2 ( 6) where, reference symbol n 2 represents the refractive index of the second lens component.

Claim 7

A large-aperture macro lens system according to claim 3 having the following numerical data: ______________________________________ f = 51.5, F/2.80˜F/5.10, 2ω = 45.5° ______________________________________ r.sub.1 = 71.9126 d.sub.1 = 2.5631 n.sub.1 = 1.72916 ν.sub.1 = 54.68 r.sub.2 = -171.0158 d.sub.2 = 0.1350 r.sub.3 = 19.7855 d.sub.3 = 3.1449 n.sub.2 = 1.77250 ν.sub.2 = 49.66 r.sub.4 = 34.9886 d.sub.4 = 0.7600 r.sub.5 = 93.2117 d.sub.5 = 1.2822 n.sub.3 = 1.58267 ν.sub.3 = 46.33 r.sub.6 = 16.3528 d.sub.6 = D.sub.1 r.sub.7 = -18.8909 d.sub.7 = 3.0858 n.sub.4 = 1.75520 ν.sub.4 = 2.751 r.sub.8 = 206.0456 d.sub.8 = 5.0491 n.sub.5 = 1.77250 ν.sub.5 = 49.66 r.sub.9 = -23.1076 d.sub.9 = 0.1650 r.sub.10 = 47.7170 d.sub.10 = 3.2747 n.sub.6 = 1.77250 ν.sub.6 = 49.66 r.sub.11 = -139.1554 d.sub.11 = D.sub.2 r.sub.12 = -377.3011 d.sub.12 = 1.5000 n.sub.7 = 1.51633 ν.sub.7 = 64.15 r.sub.13 = 31.4655 d.sub.13 = 1.6000 r.sub.14 = 315.7777 d.sub.14 = 2.6094 n.sub.8 = 1.58267 ν.sub.8 = 46.33 r.sub.15 = -73.0544 D.sub.1 D.sub.2 Infinit Distance 6.291 0.990 -0.5X 10.016 3.412 -1.0X 9.016 7.868 ______________________________________ the stop is arranged 3 mm in front of the seventh surface (r 7 ) |f.sub.3 |/f=2.597, ΔD.sub.1 =1.081 where, reference symbols r 1 , r 2 , . . . respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 , d 2 , . . . respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 , . . . respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 , . . . respectively represent Abbe's numbers of respective lenses.

Claim 8

A large-aperture macro lens system according to claim 3 having the following numerical data: ______________________________________ f = 51.5, F/2.83˜F/5.11, 2ω = 45.5° ______________________________________ r.sub.1 = 70.3184 d.sub.1 = 2.5451 n.sub.1 = 1.71700 ν.sub.1 = 47.94 r.sub.2 = -153.3443 d.sub.2 = 0.1350 r.sub.3 = 19.1789 d.sub.3 = 3.1500 n.sub.2 = 1.78590 ν.sub.2 = 44.18 r.sub.4 = 34.3091 d.sub.4 = 0.6800 r.sub.5 = 83.1414 d.sub.5 = 1.2990 n.sub.3 = 1.60342 ν.sub.3 = 38.01 r.sub.6 = 15.4390 d.sub.6 = D.sub.1 r.sub.7 = -16.4628 d.sub.7 = 2.5017 n.sub.4 = 1.75520 ν.sub.4 = 27.51 r.sub.8 = -155.4760 d.sub.8 = 5.0909 n.sub.5 = 1.77250 ν.sub.5 = 49.66 r.sub.9 = -20.4045 d.sub.9 = 0.1650 r.sub. 10 = 48.3531 d.sub.10 = 3.1648 n.sub.6 = 1.71300 ν.sub.6 = 53.84 r.sub.11 = -99.7993 d.sub.11 = D.sub.2 r.sub.12 = 153.8758 d.sub.12 = 1.5900 n.sub.7 = 1.60729 ν.sub.7 = 59.38 r.sub.13 = 30.8977 d.sub.13 = 1.8300 r.sub.14 = 171.8386 d.sub.14 = 2.6597 n.sub.8 = 1.60342 ν.sub.8 = 38.01 r.sub.15 = -135.5035 D.sub.1 D.sub.2 Infinit Distance 6.900 0.727 -0.5X 10.820 2.496 -1.0X 10.620 6.935 ______________________________________ the stop is arranged 3.3 mm in front of the seventh surface (r 7 ) |f.sub.3 |/f=2.630, ΔD.sub.1 =0.389 where, reference symbols r 1 , r 2 , . . . respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 , d 2 , . .. respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 , . . . respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 , . . . respectively represent Abbe's numbers of respective lenses.

Claim 9

A large-aperture macro lens system according to claim 3 having the following numerical data: ______________________________________ f = 51.5, F/2.8˜F/5.19, 2ω = 45.5° ______________________________________ r.sub.1 = 148.9792 d.sub.1 = 2.5631 n.sub.1 = 1.72916 ν.sub.1 = 54.68 r.sub.2 = -100.8477 d.sub.2 = 0.1350 r.sub.3 = 19.6669 d.sub.3 = 3.1449 n.sub.2 = 1.77250 ν.sub.2 = 49.66 r.sub.4 = 46.5278 d.sub.4 = 1.0165 r.sub.5 = 370.0493 d.sub.5 = 1.2822 n.sub.3 = 1.58267 ν.sub.3 = 46.33 r.sub.6 = 16.1179 d.sub.6 = D.sub.1 r.sub.7 = -17.9561 d.sub.7 = 2.0000 n.sub.4 = 1.75520 ν.sub.4 = 27.51 r.sub.8 = -359.3300 d.sub.8 = 4.0000 n.sub.5 = 1.77250 ν.sub.5 = 49.66 r.sub.9 = -21.1552 d.sub.9 = 0.1650 r.sub. 10 = 58.7760 d.sub.10 = 3.2747 n.sub.6 = 1.77250 ν.sub.6 = 49.66 r.sub.11 = -74.8374 d.sub.11 = D.sub.2 r.sub.12 = -303.7594 d.sub.12 = 1.5000 n.sub.7 = 1.51633 ν.sub.7 = 64.15 r.sub.13 = 34.8188 d.sub.13 = 1.8245 r.sub.14 = -379.9382 d.sub.14 = 2.5841 n.sub.8 = 1.56732 ν.sub.8 = 42.83 r.sub.15 = -57.1724 D.sub.1 D.sub.2 Infinit Distance 6.291 0.990 -0.5X 10.152 4.715 -1.0X 10.127 8.399 ______________________________________ the stop is arranged 3 mm in front of the seventh surface (r 7 ) |f.sub.3 |f=2.569, ΔD.sub.1 =0.327 where, reference symbols r 1 .r 2 . . . respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 , d 2 , . . . respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 , . . . respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 , . . . respectively represent Abbe's numbers of respective lenses.

Claim 10

A large-aperture macro lens system according to claim 3 having the following numerical data: ______________________________________ f = 51.5, F/2.86˜F/5.17, 2ω = 45.5° ______________________________________ r.sub.1 = 61.2176 d.sub.1 = 2.5000 n.sub.1 = 1.72000 ν.sub.1 = 50.25 r.sub.2 = -213.6049 d.sub.2 = 0.1500 r.sub.3 = 18.2860 d.sub.3 = 3.0000 n.sub.2 = 1.78590 ν.sub.2 = 44.18 r.sub.4 = 29.1936 d.sub.4 = 0.7200 r.sub.5 = 60.8301 d.sub.5 = 1.2400 n.sub.3 = 1.58144 ν.sub.3 = 40.75 r.sub.6 = 14.7356 d.sub.6 = D.sub.1 r.sub.7 = -18.2868 d.sub.7 = 2.7400 n.sub.4 = 1.76180 ν.sub.4 = 27.11 r.sub.8 = 278.6021 d.sub.8 = 5.3000 n.sub.5 = 1.77250 ν.sub.5 = 49.66 r.sub.9 = -22.8068 d.sub.9 = 0.1500 r.sub.10 = 43.1647 d.sub.10 = 2.9111 n.sub.6 = 1.72000 ν.sub.6 = 50.25 r.sub.11 = -122.2355 d.sub.11 = D.sub.2 r.sub.12 = -5146.8708 d.sub.12 = 1.4000 n.sub.7 = 1.51633 ν.sub.7 = 64.15 r.sub.13 = 30.3529 d.sub.13 = 2.0800 r.sub.14 = -398.4014 d.sub.14 = 2.4100 n.sub.8 = 1.58144 ν.sub.8 = 40.75 r.sub.15 = -53.6950 D.sub.1 D.sub.2 Infinit Distance 6.900 0.727 -0.5X 10.589 2.336 -1.0X 9.990 6.107 ______________________________________ the stop is arranged 3.3 mm in front of seventh surface (r 7 ) |f.sub.3 |/f=2.734, ΔD.sub.1 =0.721 where, reference symbols r 1 , R 2 , . . . respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 , d 2 , . . . respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 , . . . respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 , . . . respectively represent Abbe's numbers of respective lenses.

Claim 11

A large-aperture macro lens system according to claim 3 having the following numerical data: ______________________________________ f = 51.5, F/2.89˜F/5.51, 2ω = 45.5° ______________________________________ r.sub.1 = 107.4559 d.sub.1 = 2.5631 n.sub.1 = 1.72916 ν.sub.1 = 54.68 r.sub.2 = -134.0176 d.sub.2 = 0.135 r.sub.3 = 18.5240 d.sub.3 = 3.1449 n.sub.2 = 1.77250 ν.sub.2 = 49.66 r.sub.4 = 35.1161 d.sub.4 = 0.8000 r.sub.5 = 131.5691 d.sub.5 = 1.2822 n.sub.3 = 1.58267 ν.sub.3 = 46.33 r.sub.6 = 15.8882 d.sub.6 = D.sub.1 r.sub.7 = -15.1976 d.sub.7 = 1.8825 n.sub.4 = 1.75520 ν.sub.4 = 27.51 r.sub.8 = -359.3300 d.sub.8 = 3.5481 n.sub.5 = 1.78590 ν.sub.5 = 44.18 r.sub.9 = -17.9921 d.sub.9 = 0.1650 r.sub. 10 = 80.9828 d.sub.10 = 3.2747 n.sub.6 = 1.77250 ν.sub.6 = 49.66 r.sub.11 = -102.7116 d.sub.11 = D.sub.2 r.sub.12 = 102.5518 d.sub.12 = 1.5000 n.sub.7 = 1.51633 ν.sub.7 = 64.15 r.sub.13 = 38.6024 d.sub.13 = 1.0000 r.sub.14 = 160.0516 d.sub.14 = 2.5841 n.sub.8 = 1.56732 ν.sub.8 = 42.83 r.sub.15 = -231.2026 D.sub.1 D.sub.2 Infinit Distance 9.900 1.533 -0.5X 11.247 3.259 -1.0X 10.248 14.177 ______________________________________ the stop is arranged 3.3 mm in front of the seventh surface (r 7 ) |f.sub.3 |/f=8.680, ΔD.sub.1 =1.359 where, reference symbols r 1 , r 2 , . . . respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 , d 2 , . . . respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 , . . . respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 , . . . respectively represent Abbe's numbers of respective lenses.

Claim 12

A large-aperture macro lens system according to claim 3 having the following numerical data: ______________________________________ f = 51.5, F/2.8˜F/5.22, 2ω = 45.5° ______________________________________ r.sub.1 = 40.5017 d.sub.1 = 3.6069 n.sub.1 = 1.72916 ν.sub.1 = 54.68 r.sub.2 = 1165.0549 d.sub.2 = 0.1350 r.sub.3 = 18.9963 d.sub.3 = 3.1449 n.sub.2 = 1.77250 ν.sub.2 = 49.66 r.sub.4 = 29.6782 d.sub.4 = 1.4000 r.sub.5 = 90.0652 d.sub.5 = 1.7000 n.sub.3 = 1.65016 ν.sub.3 = 39.39 r.sub.6 = 12.8155 d.sub.6 = D.sub.1 r.sub.7 = -11.5012 d.sub.7 = 1.8500 n.sub.4 = 1.80518 ν.sub.4 = 25.43 r.sup.8 = -14.3165 d.sub.8 = 0.1500 r.sub.9 = 62.8013 d.sub.9 = 4.0000 n.sub.5 = 1.72916 ν.sub.5 = 54.68 r.sub.10 = -24.7292 d.sub.10 = D.sub.2 r.sub.11 = -118.5352 d.sub.11 = 1.4000 n.sub.6 = 1.58144 ν.sub.6 = 40.75 r.sub.12 = 31.9202 d.sub.12 = 1.6000 r.sub.13 = -392.9991 d.sub.13 = 3.1440 n.sub.7 = 1.58913 ν.sub.7 = 60.97 r.sub.14 = -37.2800 D.sub.1 D.sub.2 Infinit Distance 8.302 0.600 -0.5X 8.823 2.417 -1.0X 8.802 6.206 ______________________________________ the stop is arranged 4 mm in front of the seventh surface (r 7 ) |f.sub.3 |/f=2.579, ΔD.sub.1 =0.128 where, reference symbols r 1 , r 2 , . . . respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 , d 2 , . . . respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 , . . . respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 , . . . respectively represent Abbe's numbers of respective lenses.