Wide angle zoom lens having a high variation ratio

Claim 2

A wide angle zoom lens system exhibiting a high variation zoom ratio, said wide angle zoom lens system comprising in order from the object side a first lens group I having a positive focal length f I , a second lens group II having a negative focal length f II , a third lens group III having a positive focal length f III , said second lens group II and said third lens group III being axially movable along the optical axis so that each produces a component of said increasing variation effect, characterized by: (a) the amount of axial movement X I (f) of the first lens group I and the amount of axial movement X III (f) of the third lens group III satisfying the following conditions: X.sub.I (f)=k(f)·X.sub.III (f), and (1) 0≦k(f)≦3.0; (2) (b) the lens system having a high zoom variation ratio equal to or greater than 2 times; and, (c) the lens system satisfying the following conditions: 1.70<f.sub.I /f.sub.S <5.0 (3) 0.60<|f.sub.II |/f.sub.S <1.50 (4) 0<l.sub.I·II /f.sub.S <0.2 (5) 0.6<l.sub.II·III /f.sub.S <1.8 (6) wherein: f S is the overall focal length at the wide angle position; l I ·II is the aerial space between the first lens group I and the second lens group II at the wide angle position; and l II ·III is the aerial space between the second lens group II and the third lens group III at the wide angle position.

Claim 3

The wide angle zoom lens system as recited in claim 1, further comprising a lens group III', said lens group III' having a positive focal length f III' , said lens group III' being fixed along the optical axis so as not to be movable during zooming, and said lens group III' being disposed on the object side of said third lens group III.

Claim 4

The wide angle zoom lens system as recited in claim 1, further comprising a lens group III', said lens group III' having a positive focal length f III' , said lens group III' being fixed along the optical axis so as not to be movable during zooming, and said lens group III' being disposed on the image side of said third lens group III.

Claim 5

A wide angle zoom lens system exhibiting a high variation zoom ratio, grouped in first, second and third lens groups I, II and III, in order from the object side to the image side, said first lens group I having a positive focal length f I , said first lens group I having at least two lenses, with the first lens being a negative lens having a strong negative lens power in the image direction and with said second lens and any additional lenses being positive lenses, said first lens being optically cemented to said second lens, said second lens group II having a negative focal length f II , said second lens group II having at least three lenses, with the first lens being a negative lens having a strong negative lens power on the image side surface, with the second lens being a negative lens having a negative lens power on the image side surface, and with the third lens being a positive lens having a positive lens power on the object side surface, said third lens group III having a positive focal length f III and having at least four lenses, said lenses in order from the object side to the image side divided into a first positive lens unit, a negative lens unit and a second positive lens unit, said first positive lens unit having at least two positive lenses, said negative lens unit having a negative lens, and said second positive lens unit having at least one positive lens, wherein said second lens group II and said third lens group III are each independently moved for zooming, the lens system satisfying the following conditions: X.sub.I (f)=k(f) X.sub.III (f) (1) 0≦k(f)≦3.0 (2) 1.7<f.sub.I /f.sub.S <5.0 (3) 0.6<|f.sub.II |/f.sub.S <1.5 (4) n.sub.I >1.65 (5) ν.sub.I <35 (6) 2r.sub.a <r.sub.b ( 7) r.sub.c <r.sub.b ( 8) ν.sub.IIN -ν.sub.IIP >15 (9) 0.4<r.sub.d /f.sub.III <0.8 (10) wherein: X I (f) is the amount of axial movement of the first lens group I; X III (f) is the amount of axial movement of the third lens group III; f S is the overall focal length at the wide angle position; n I is the average value of the refractive indices of the positive lenses in the first lens group I; ν I is the Abbe number of the negative lens in the first lens group I; r a is the radius of curvature in the image direction of the first lens of the second lens group II; r b is the radius of curvature in the image direction of the second lens of the second lens group II; r c is the radius of curvature in the object direction of the third lens of the second-lens group II; ν IIN is the average of the Abbe numbers of the first and second lenses of the second lens group II; ν IIP is the Abbe number of the third lens of the second lens group II; and r d is the radius of curvature in the image direction of the negative lens unit of said third lens group III.

Claim 6

A wide angle zoom lens system exhibiting a high variation zoom ratio, grouped in first, second and third lens groups I, II and III, in order from the object side to the image side, said first lens group I having a positive focal length f I , said first lens group I having at least two lenses, with the first lens being a negative lens having a strong negative lens power in the image direction and with said second lens and any additional lenses being positive lenses, said first lens being optically cemented to said second lens, said second lens group II having a negative focal length f II , said second lens group II having at least three lenses, with the first lens being a negative lens having a strong negative lens power on the image side surface, with the second lens being a negative lens having a negative lens power on the image side surface, and with the third lens being a positive lens having a positive lens power on the object side surface, said third lens group III having a positive focal length f III and having at least four lenses, said lenses in order from the object side to the image side divided into a first positive lens unit, a negative lens unit and a second positive lens unit, said first positive lens unit having at least two positive lenses, said negative lens unit having a negative lens, and said second positive lens unit having at least one positive lens, wherein said second lens group II and said third lens group III are each independently moved for zooming, the lens system satisfying the following conditions: X.sub.I (f)=k(f) X.sub.III (f) (1) 0≦k(f)≦3.0 (2) 1.7<f.sub.I /f.sub.S <5.0 (3) 0.6<|f.sub.II |/f.sub.S <1.5 (4) n.sub.I >1.65 (5) ν.sub.I <35 (6) 2r.sub.a <r.sub.b ( 7) r.sub.c <r.sub.b ( 8) ν.sub.IIN -ν.sub.IIP >15 (9) 0.4<r.sub.d /f.sub.III <0.8 (10) wherein: X I (f) is the amount of axial movement of the first lens group I; X III (f) is the amount of axial movement of the third lens group III; f S is the overall focal length at the wide angle position; n I is the average value of the refractive indices of the positive lenses in the first lens group I; ν I is the Abbe number of the negative lens in the first lens group I; r a is the radius of curvature in the image direction of the first lens of the second lens group II; r b is the radius of curvature in the image direction of the second lens of the second lens group II; r c is the radius of curvature in the object direction of the third lens of the second-lens group II; ν IIN is the average of the Abbe numbers of the first and second lenses of the second lens group II; ν IIP is the Abbe number of the third lens of the second lens group II; and r d is the radius of curvature in the image direction of the negative lens unit of said third lens group III.

Claim 7

The wide angle zoom lens system as recited in claim 4, further comprising a lens group III', said lens group III' having a positive focal length f III' , said lens groups III' being fixed along the optical axis so as not to be movable during zooming, said lens group III' being disposed on the object side of said third lens group III, and wherein said third lens group includes a single positive lens and satisfies the following condition: 1.5<f.sub.III' /f.sub.S <4.0.

Claim 8

The wide angle zoom lens system as recited in claim 4, further comprising a lens group III', said lens group III' having a positive focal length f III' , said lens group III' being fixed along the optical axis so as not to be movable during zooming, said lens group III' being disposed on the image side of said third lens group III, and wherein said third lens group includes a single positive lens and satisfies the following condition: 3.5<f.sub.III' /f.sub.S <10.0.

Claim 9

The wide angle zoom lens system as recited in claim 1, wherein said zoom lens system comprises ten lenses grouped in three lens groups, in order from the object side to the image side, the first lens group lens having two lenses, with the first lens L 1 being a negative lens and with the second lens L 2 being a positive lens, the second group having three lenses, with the third and fourth lenses L 3 , L 4 being negative lenses and with the fifth lens L 5 being a positive lens, and the third lens group having five lenses, with the sixth, seventh and eighth lenses L 6 , L 7 and L 8 being positive lenses, with the ninth lens L 9 being a negative lens and with the tenth lens L 10 being a negative lens, wherein the radii of curvature r 1 to r 19 , the spacing or thickness d 1 to d 18 , the refractive indices n 1 to n 10 and the Abbe numbers ν 1 to ν 10 of the lenses are as follows: __________________________________________________________________________ overall focal length f = 36.0-83.0 viewing angle 2ω = 63.6°-28.2° radius of spacing and refractive Lens curvature thickness index at d-line Abbe No. __________________________________________________________________________ r.sub.1 = 77.763 first L.sub.1 d.sub.1 = 2.00 n.sub.1 = 1.80518 ν.sub.1 = 25.4 lens r.sub.2 = 42.254 group L.sub.2 d.sub.2 = 8.28 n.sub.2 = 1.81600 ν.sub.2 = 46.6 I r.sub.3 = 391.376 d.sub.3 = 0.950-14.980-27.033 r.sub.4 = 156.329 L.sub.3 d.sub.4 = 1.20 n.sub.3 = 1.88300 ν.sub.3 = 40.8 r.sub.5 = 21.510 d.sub.5 = 10.61 second r.sub.6 = -54.115 lens L.sub.4 d.sub.6 = 1.11 n.sub.4 = 1.61800 ν.sub.4 = 63.4 group r.sub.7 = 102.401 II d.sub.7 = 0.10 r.sub.8 = 45.372 L.sub.5 d.sub.8 = 4.45 n.sub.5 = 1.76182 ν.sub.5 = 26.6 r.sub.9 = -209.533 d.sub.9 = 27.980-13.950-1.897 r.sub.10 = 77.719 L.sub.6 d.sub.10 = 2.65 n.sub.6 = 1.81600 ν.sub.6 = 46.6 r.sub.11 = -254.167 d.sub.11 = 0.57 r.sub.12 = 30.925 L.sub.7 d.sub.12 = 2.57 n.sub.7 = 1.80400 ν.sub.7 = 46.6 r.sub.13 = 64.075 d.sub.13 = 2.13 third r.sub.14 = 25.967 lens L.sub.8 d.sub.14 = 4.36 n.sub.8 = 1.60311 ν.sub.8 = 60.7 group r.sub.15 = 69.262 III d.sub.15 = 1.06 r.sub.16 = 319.085 L.sub.9 d.sub.16 = 5.12 n.sub.9 = 1.84666 ν.sub.9 = 23.9 r.sub.17 = 18.078 d.sub.17 = 5.62 r.sub.18 = 71.319 L.sub.10 d.sub.18 = 4.50 n.sub.10 = 1.50137 ν.sub.10 = 56.4 r.sub.19 = -34.849 __________________________________________________________________________

Claim 10

The wide angle zoom lens system as recited in claim 1, wherein said zoom lens system comprises eleven lenses grouped in three lens groups, in order from the object side to the image side, the first lens group having three lenses, with the first lens L 1 being a negative lens and with the second and third lenses L 2 , L 3 being positive lenses, the second group having three lenses, with the fourth and fifth lenses L 4 , L 5 being negative lenses, and with the sixth lens L 6 being a positive lens, and the third lens group having five lenses, with the seventh, eighth and ninth lenses L 7 , L 8 and L 9 being positive lenses, with the tenth lens L 10 being a negative lens, with the eleventh lens L 11 being a positive lens, wherein the radii of curvature r 1 to r 21 , the spacing or thickness d 1 to d 20 , the refractive indices n 1 to n 11 , and the Abbe numbers ν 1 to ν 11 of the lenses are as follows: __________________________________________________________________________ overall focal length f = 35.996-82.997 viewing angle 2ω = 64.2°-27.8° radius of spacing and refractive Lens curvature thickness index at d-line Abbe No. __________________________________________________________________________ r.sub.1 = 3092.123 L.sub.1 d.sub.1 = 1.60 n.sub.1 = 1.84666 ν.sub.1 = 23.9 r.sub.2 = 104.769 first L.sub.2 d.sub.2 = 4.33 n.sub.2 = 1.81600 ν.sub.2 = 46.6 lens r.sub.3 = -570.048 group d.sub.3 = 0.16 I r.sub.4 = 65.977 L.sub.3 d.sub.4 = 4.49 n.sub.3 = 1.65160 ν.sub.3 = 58.6 r.sub.5 = 2158.113 d.sub.5 = 0.980-13.236-19.746 r.sub.6 = 11866.281 L.sub.4 d.sub.6 = 1.45 n.sub.4 = 1.88300 ν.sub.4 = 40.8 r.sub.7 = 21.855 d.sub.7 = 9.06 second r.sub.8 = -45.651 lens L.sub.5 d.sub.8 = 1.19 n.sub.5 = 1.61800 ν.sub.5 = 63.4 group r.sub.9 = 185.600 II d.sub.9 = 0.10 r.sub.10 = 48.905 L.sub.6 d.sub.10 = 3.40 n.sub.6 = 1.80518 ν.sub.6 = 25.4 r.sub.11 = -168.190 d.sub.11 = 27.770-15.077-2.376 r.sub.12 = 125.990 L.sub.7 d.sub.12 = 2.28 n.sub.7 = 1.80400 ν.sub.7 = 46.6 r.sub.13 = -138.952 d.sub.13 = 0.28 r.sub.14 = 38.738 L.sub.8 d.sub.14 = 2.97 n.sub.8 = 1.80400 ν.sub.8 = 46.6 r.sub.15 = 118.930 d.sub.15 = 0.10 r.sub.16 = 26.088 L.sub.9 d.sub.16 = 3.11 n.sub.9 = 1.53172 ν.sub.9 = 48.9 third r.sub.17 = 68.374 lens d.sub.17 = 2.57 group r.sub.18 = 281.100 III L.sub.10 d.sub.18 = 9.66 n.sub.10 = 1.84666 ν.sub.10 = 23.9 r.sub.19 = 21.464 d.sub.19 = 1.89 r.sub.20 = 85.120 L.sub.11 d.sub.20 = 4.70 n.sub.11 = 1.48749 ν.sub.11 = 70.1 r.sub.21 = -26.537 __________________________________________________________________________

Claim 11

The wide angle zoom lens system as recited in claim 1, wherein said zoom lens system comprises eleven lenses grouped in three lens groups, in order from the object side to the image side, the first lens group having three lenses, with the first lens L 1 being a negative lens and with the second and third lenses L 2 , L 3 being positive lenses, the second group having three lenses, with the fourth and fifth lenses L 4 , L 5 being negative lenses, and with the sixth lens L 6 being a positive lens, and the third lens group having five lenses, with the seventh, eighth and ninth lenses L 7 , L 8 and L 9 being positive lenses, with the tenth lens L 10 being a negative lens, with the eleventh lens L 11 being a positive lens, wherein the radii of curvature r 1 to r 21 , the spacing or thickness d 1 to d 20 , the refractive indices n 1 to n 11 , and the Abbe numbers ν 1 to ν 11 of the lenses are as follows: __________________________________________________________________________ overall focal length f = 36.011-83.003 viewing angle 2ω = 64.8°-28.0° radius of spacing and refractive Lens curvature thickness index of d-line Abbe No. __________________________________________________________________________ r.sub.1 = 12988.0 L.sub.1 d.sub.1 = 1.60 n.sub.1 = 1.84666 ν.sub.1 = 23.9 r.sub.2 = 104.685 first L.sub.2 d.sub.2 = 4.49 n.sub.2 = 1.81600 ν.sub.2 = 46.6 lens r.sub.3 = -395.931 group d.sub.3 = 0.16 I r.sub.4 = 45.751 L.sub.3 d.sub.4 = 5.74 n.sub.3 = 1.58913 ν.sub.3 = 61.1 r.sub.5 = 458.050 d.sub.5 = 1.090-11.360-15.283 r.sub.6 = 9802.181 L.sub.4 d.sub.6 = 1.45 n.sub.4 = 1.88300 ν.sub.4 = 40.8 r.sub.7 = 20.159 d.sub.7 = 8.43 r.sub.8 = -40.152 second L.sub.5 d.sub.8 = 1.18 n.sub.5 = 1.61800 ν.sub.5 = 63.4 lens r.sub.9 = 94.619 group d.sub.9 = 0.10 II r.sub.10 = 45.094 L.sub.6 d.sub.10 = 3.68 n.sub.6 = 1.80518 ν.sub.6 = 25.4 r.sub.11 = -108.258 d.sub.11 = 27.284-15.404-2.365 r.sub.12 = -1335.144 L.sub.7 d.sub.12 = 2.02 n.sub.7 = 1.80400 ν.sub.7 = 46.6 r.sub.13 = -73.057 d.sub.13 = 0.28 r.sub.14 = 43.537 L.sub.8 d.sub.14 = 2.40 n.sub.8 = 1.80400 ν.sub.8 = 46.6 r.sub.15 = 155.661 d.sub.15 = 0.10 r.sub.16 = 24.992 third L.sub.9 d.sub.16 = 4.31 n.sub.9 = 1.53172 ν.sub.9 = 48.9 lens r.sub.17 = 815.087 group d.sub.17 = 0.97 III r.sub.18 = -137.003 L.sub.10 d.sub.18 = 10.44 n.sub.10 = 1.84666 ν.sub.10 = 23.9 r.sub.19 = 21.786 d.sub.19 = 2.86 r.sub.20 = 227.782 L.sub.11 d.sub.20 = 3.76 n.sub.11 = 1.48749 ν.sub.11 = 70.1 r.sub.21 = -25.281 __________________________________________________________________________

Claim 12

The wide angle zoom lens system as recited in claim 1, wherein said zoom lens system comprises ten lenses grouped in three lens groups, in order from the object side to the image side, the first lens group having two lenses, with the first lens L 1 being a negative lens and with the second lens L 2 being a positive lens, the second group having three lenses, with the third and fourth lenses L 3 , L 4 being negative lenses, and with the fifth lens L 5 being a positive lens, and the third lens group having five lenses, with the sixth, seventh and eighth lenses L 6 , L 7 and L 8 being positive lenses, with the ninth lens L 9 being a negative lens and with the tenth lens L 10 being a positive lens, wherein the radii of curvature r 1 to r 19 , the spacing or thickness d 1 to d 18 , the refractive indices n 1 to n 10 and the Abbe numbers ν 1 to ν 10 of the lenses are as follows: __________________________________________________________________________ overall focal length f = 36.009-83.040 viewing angle 2ω = 64.2°-28.4° radius of spacing and refractive Lens curvature thickness index of d-line Abbe No. __________________________________________________________________________ r.sub.1 = 72.662 first L.sub.1 d.sub.1 = 2.00 n.sub.1 = 1.80518 ν.sub.1 = 25.4 lens r.sub.2 = 40.993 group L.sub.2 d.sub.2 = 8.35 n.sub.2 = 1.81600 ν.sub.2 = 46.6 I r.sub.3 = 387.611 d.sub.3 = 0.496-12.246-18.987 r.sub.4 = 222.420 L.sub.3 d.sub.4 = 1.20 n.sub.3 = 1.86300 ν.sub.3 = 41.5 r.sub.5 = 22.464 d.sub.5 = 11.33 r.sub.6 = -67.497 second L.sub.4 d.sub.6 = 1.40 n.sub.4 = 1.61800 ν.sub.4 = 63.4 lens r.sub.7 = 66.399 group d.sub.7 = 0.13 II r.sub.8 = 42.414 L.sub.5 d.sub.8 = 4.01 n.sub.5 = 1.76182 ν.sub.5 = 26.6 r.sub.9 = -288.874 d.sub.9 = 29.437-14.256-0.473 r.sub.10 = 57.417 L.sub.6 d.sub.10 = 2.37 n.sub.6 = 1.81600 ν.sub.6 = 46.6 r.sub.11 = -336.181 d.sub.11 = 0.09 r.sub.12 = 30.392 L.sub.7 d.sub.12 = 2.56 n.sub.7 = 1.80400 ν.sub.7 = 46.6 r.sub.13 = 65.991 d.sub.13 = 2.48 r.sub.14 = 31.617 third L.sub.8 d.sub.14 = 2.05 n.sub.8 = 1.64000 ν.sub.8 = 60.1 lens r.sub.15 = 73.034 group d.sub.15 = 1.19 III r.sub.16 = -1264.582 L.sub.9 d.sub.16 = 6.04 n.sub.9 = 1.84666 ν.sub.9 = 23.9 r.sub.17 = 19.660 d.sub.17 = 6.00 r.sub.18 = 109.201 L.sub.10 d.sub.18 = 4.50 n.sub.10 = 1.54739 ν.sub.10 = 53.6 r.sub.19 = -34.106 __________________________________________________________________________

Claim 13

The wide angle zoom lens system as recited in claim 5, wherein said zoom lens system comprises eleven lenses group in four lens groups, in order from the object side to the image side, the first lens group I having two lenses, with the first lens L 1 being a negative lens and with the second lens L 2 being a positive lens, the second lens group II having three lenses, with the third and fourth lenses L 3 , L 4 being negative lenses and with the fifth lens L 5 being a positive lens, the lens group III' having one lens, with the sixth lens L 6 being a positive lens, and the third lens group III having five lenses, with the seventh, eighth and ninth lenses L 7 , L 8 and L 9 being positive lenses, with the tenth lens L 10 being a negative lens and with the eleventh lens L 11 being a positive lens, and wherein the radii of curvature r 1 to r 21 , the spacing or thickness d 1 to d 21 , the refractive indices n 1 to n 11 and the Abbe numbers ν 1 to ν 11 of the lenses are as follows: __________________________________________________________________________ overall focal length f = 28.978-77.5 viewing angle 2ω = 78.0°-30.0° radius of spacing and refractive lens curvature thickness index at d-line Abbe No. __________________________________________________________________________ r.sub.1 = 42.227 first L.sub.1 d.sub.1 = 1.39 n.sub.1 = 1.84666 ν.sub.1 = 23.9 lens r.sub.2 = 33.485 group L.sub.2 d.sub.2 = 7.28 n.sub.2 = 1.69680 ν.sub.2 = 56.5 I r.sub.3 = 208.250 d.sub.3 = 0.78-11.68-17.66 r.sub.4 = 131.553 L.sub.3 d.sub.4 = 1.20 n.sub.3 = 1.88300 ν.sub.3 = 40.8 r.sub.5 = 17.279 d.sub.5 = 7.02 second r.sub.6 = -76.950 lens L.sub.4 d.sub.6 = 1.19 n.sub.4 = 1.81600 ν.sub.4 = 46.6 group r.sub.7 = 42.130 II d.sub.7 = 0.10 r.sub.8 = 30.339 L.sub.5 d.sub.8 = 4.00 n.sub.5 = 1.80518 ν.sub.5 = 25.4 - r.sub.9 = -2221.231 d.sub.9 = 17.85-6.95-0.97 lens r.sub.10 = 73.840 group L.sub.6 d.sub.10 = 3.84 n.sub.6 = 1.74400 ν.sub.6 = 44.7 III' r.sub.11 = -248.553 d.sub.11 = 21.91-12.33-2.43 r.sub.12 = 49.700 L.sub.7 d.sub.12 = 1.61 n.sub.7 = 1.81600 ν.sub.7 = 46.6 r.sub.13 = 245.000 d.sub.13 = 0.16 r.sub.14 = 35.991 L.sub.8 d.sub.14 = 2.92 n.sub.8 = 1.77250 ν.sub.8 = 49.6 r.sub.15 = -146.696 d.sub.15 = 1.14 r.sub.16 = -57.377 third L.sub.9 d.sub.16 = 11.02 n.sub.9 = 1.80518 ν.sub.9 = 25.4 lens r.sub.17 = 27.625 group d.sub.17 = 3.41 III r.sub.18 = -65.656 L.sub.10 d.sub.18 = 2.34 n.sub.10 = 1.84100 ν.sub.10 = 43.2 r.sub.19 = -32.889 d.sub.19 = 0.10 r.sub.20 = -106.721 L.sub.11 d.sub.20 = 2.32 n.sub.11 = 1.81600 ν.sub.11 = 46.6 r.sub.21 = -46.694 __________________________________________________________________________

Claim 14

The wide angle zoom lens system as recited in claim 6, wherein said zoom lens system comprises twelve lens grouped in four lens groups, in order from the object side to the image side, the first lens group I having two lenses, with the first lens L 1 being a negative lens and with the second lens L 2 being a positive lens, the second lens group II having three lenses, with the third and fourth lenses L 3 , L 4 being negative lenses and with the fifth lens L 5 being a positive lens, the third lens group III having a first positive lens group, a negative lens group, and a second positive lens group, in the order from the object side to the image side, the first positive lens group having three lenses, with the sixth, seventh and eighth lenses L 6 , L 7 , L 8 all being positive lenses, the negative lens group having an lens, with the ninth lens L 9 being a negative lens, the second positive lens group having two lenses, with the tenth and eleventh lenses L 10 , L 11 both being positive lenses, and the lens group III' having one lens, with the twelfth lens L 12 being a positive lens, and wherein the radii of curvature r 1 to r 23 , the spacing or thickness d 1 to d 22 , the refractive indices n 1 to n 12 and the Abbe numbers ν 1 to ν 12 of the lenses are as follows: __________________________________________________________________________ overall focal length f = 28.80-83.00 viewing angle 2ω = 76.2-28.6 radius of spacing and refractive lens curvature thickness index at d-line Abbe No. __________________________________________________________________________ r.sub.1 = 98.268 first L.sub.1 d.sub.1 = 2.00 n.sub.1 = 1.80518 ν.sub.1 = 25.4 lens r.sub.2 = 56.851 group L.sub.2 d.sub.2 = 8.06 n.sub.2 = 1.81600 ν.sub.2 = 46.8 I r.sub.3 = 7200.000 d.sub.3 = 0.98-9.37-27.63 r.sub.4 = 128.547 L.sub.3 d.sub.4 = 1.20 n.sub.3 = 1.86300 ν.sub.3 = 41.7 r.sub. 5 = 18.176 d.sub.5 = 8.89 second r.sub.6 = -75.123 lens L.sub.4 d.sub.6 = 1.40 n.sub.4 = 1.61800 ν.sub.4 = 63.4 group r.sub.7 = 62.479 II d.sub.7 = 0.10 r.sub.8 = 33.000 L.sub.5 d.sub.8 = 3.89 n.sub.5 = 1.76182 ν.sub.5 = 26.6 r.sub.9 = 2639.805 d.sub.9 = 32.08-23.69-5.43 r.sub.10 = 38.025 L.sub.6 d.sub.10 = 1.80 n.sub.6 = 1.81600 ν.sub.6 = 46.8 r.sub.11 = 126.500 d.sub.11 = 0.10 r.sub.12 = 23.370 L.sub.7 d.sub.12 = 1.87 n.sub.7 = 1.80400 ν.sub.7 = 46.6 r.sub.13 = 40.949 d.sub.13 = 3.54 r.sub.14 = 27.773 third L.sub.8 d.sub.14 = 1.78 n.sub.8 = 1.64000 ν.sub.8 = 60.2 lens r.sub.15 = 63.990 group d.sub.15 = 1.50 III r.sub.16 = -505.700 L.sub.9 d.sub.16 = 2.78 n.sub.9 = 1.84666 ν.sub.9 = 23.9 r.sub.17 = 18.425 d.sub.17 = 2.02 r.sub.18 = 206.849 L.sub.10 d.sub.18 = 1.80 n.sub.10 = 1.55361 ν.sub.10 = 51.2 r.sub.19 = -55.409 d.sub.19 = 0.50 r.sub.20 = 755.310 L.sub.11 d.sub.20 = 1.80 n.sub.11 = 1.59270 ν.sub.11 = 35.3 r.sub.21 = -60.691 d.sub.21 = 1.09-8.22-36.95 lens r.sub.22 = 52.200 group L.sub.12 d.sub.22 = 2.50 n.sub.12 = 1.58144 ν.sub.12 = 40.7 III' r.sub.23 = 102.000 __________________________________________________________________________