High speed varifocal objective system

Claim 2

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens with a separation of less than 10 percent of the individual focal length of said first component; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; the individual focal lengths fI of said first component, fII of said second component, fIII of said third component, fIV of said fourth component and fV of said basic objective being related to one another as follows: 2.5 fV < fI < 3fV 0.7 fV < fII < fV 1.75 fV < fIII < 2.5 fV 1.4 fV < fIV < 2 fV fI > fIII > fIV > fV > fII ; said basic objective consisting of a positive first singlet, a positive second singlet, a negative third singlet and a positive fourth singlet air-spaced from one another; the relative numerical values of the radii r15 - r22 and of the thicknesses and separations d15 - d21 of said first singlet L8, said second singlet L9, said third singlet L10 and said fourth singlet L11, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r15 +22.56 +0.0307 L8 (d15 2.55 1.6940 54.4 r16 -106.20 +0.0065 d16 0.05 air space r17 +13.29 +0.0522 L9 (d17 1.80 1.6940 54.4 r18 +30.04 -0.0231 d18 1.40 air space r19 -36.19 -0.0224 L10 (d19 4.90 1.8126 25.2 r20 +10.99 -0.0739 d20 2.25 air space r21 +32.69 +0.0219 L11 (d21 2.45 1.7161 53.6 r22 +14.61 +0.0490

Claim 3

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2, said first negative lens member L3, said second negative lens member L4, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe number Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/rand separations r1 +41.42 +0.0191 L1 (d1 1.80 1.7917 25.8 r2 +24.03 -0.0329 d2 4.50 air space r3 +27.05 +0.0251 L2 (d3 6.00 1.6808 54.9 r4 -183.60 +0.0037 d4 16.32 air space (variable) r5 +2727.00 +0.0001 L3 (d5 1.00 1.4891 70.2 r6 +16.99 -0.0287 d6 3.70 air space r7 -29.74 -0.0164 L4 (d7 1.00 1.4891 70.2 r8 +279.40 -0.0017 d8 8.75 air space (variable) r9 -18.46 -0.0264 L5 (d9 1.00 1.4891 70.2 r10 -70.15 +0.0069 d10 4.24 air space (variable) r11 +60.03 +0.0111 L6 (d11 2.40 1.6713 41.6 r12 -32.91 +0.0203

Claim 4

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2, said first negative lens member L3, said second negative lens member L4, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe number Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/rand separations r1 +41.42 +0.0191 L1 (d1 1.80 1.7917 25.8 r2 +24.03 -0.0329 d2 4.50 air space r3 +27.05 +0.0251 L2 (d3 6.00 1.6808 54.9 r4 -183.60 +0.0037 d4 16.32 air space (variable) r5 +2727.00 +0.0001 L3 (d5 1.00 1.4891 70.2 r6 +16.99 -0.0287 d6 3.70 air space r7 -29.74 -0.0164 L4 (d7 1.00 1.4891 70.2 r8 +279.40 -0.0017 d8 8.75 air space (variable) r9 -18.46 -0.0264 L5 (d9 1.00 1.4891 70.2 r10 -70.15 +0.0069 d10 4.24 air space (variable) r11 +60.03 +0.0111 L6 (d11 2.40 1.6713 41.6 r12 -32.91 +0.0203

Claim 5

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b following said positive second lens L2a, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said first negative lens member L3, said second negative lens member L4, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 +192.35 +0.0039 L1 (d1 1.80 1.7616 27.3 r2 +39.09 -0.0194 d2 2.50 air space r2a +44.43 +0.0138 L2a (d2a 4.00 1.6167 54.8 r3a -958.00 +0.0006 d2b 0.10 air space r3b +37.56 +0.0164 L2b (d3b 3.80 1.6176 50.8 r4b Infinity + or - 0.0 d4 16.54 air space (variable) r5 +2727.00 +0.0001 L3 (d5 1.00 1.4891 70.2 r6 +16.99 -0.0287 d6 3.70 air space r7 -32.50 -0.0150 L4 (d7 1.00 1.4891 70.2 r8 +158.20 -0.0030 d8 8.55 air space (variable) r9 -18.46 -0.0264 L5 (d9 1.00 1.4891 70.2 r10 -70.15 +0.0069 d10 4.31 air space (variable) r11 +60.03 +0.0111 L6 (d11 2.40 1.671341.6 r12 -32.91 +0.0203

Claim 6

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b following said positive second lens L2a, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said first negative lens member L3, said second negative lens member L4, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 +192.35 +0.0039 L1 (d1 1.80 1.7616 27.3 r2 +39.09 -0.0194 d2 2.50 air space r2a +44.43 +0.0138 L2a (d2a 4.00 1.6167 54.8 r3a -958.00 +0.0006 d2b 0.10 air space r3b +37.56 +0.0164 L2b (d3b 3.80 1.6176 50.8 r4b Infinity + or - 0.0 d4 16.54 air space (variable) r5 +2727.00 +0.0001 L3 (d5 1.00 1.4891 70.2 r6 +16.99 -0.0287 d6 3.70 air space r7 -32.50 -0.0150 L4 (d7 1.00 1.4891 70.2 r8 +158.20 -0.0030 d8 8.55 air space (variable) r9 -18.46 -0.0264 L5 (d9 1.00 1.4891 70.2 r10 -70.15 +0.0069 d10 4.31 air space (variable) r11 +60.03 +0.0111 L6 (d11 2.40 1.671341.6 r12 -32.91 +0.0203

Claim 7

A varifocal objective system comprising a bAsic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separationsr1 +181.00 +0.0042 L1 (d1 1.80 1.7616 27.3 r2 +38.99 -0.0195 d2 2.50 air space r2a +43.00 +0.0141 L2a (d2a 4.00 1.6099 56.3 r3a -451.00 +0.0013 d2b 0.10 air space r3b +35.96 +0.0173 L2b (d3b 3.80 1.6254 56.6 r4b +641.50 -0.0009 d4 15.51 air space (variable) r5 +11342.00 +0.0001 L3 (d5 1.00 1.6228 60.0 r6 +19.23 -0.0323 d6 3.70 air space r7a -43.87 -0.0185 L4a (d7a 2.40 1.8126 25.2 r7b -20.01 +0.0094 L4b (d7b 1.00 1.6228 60.0 r8b +79.77 -0.0078 d8 7.33 air space (variable) r9 -14.20 -0.0360 L5 (d9 1.00 1.5120 64.0 r10 -31.49 +0.0162 d10 4.17 air space (variable) r11 +60.03 +0.0104 L6 (d11 2.40 1.6250 52.8 r12 -29.54 +0.0211

Claim 8

A varifocal objective system comprising a bAsic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separationsr1 +181.00 +0.0042 L1 (d1 1.80 1.7616 27.3 r2 +38.99 -0.0195 d2 2.50 air space r2a +43.00 +0.0141 L2a (d2a 4.00 1.6099 56.3 r3a -451.00 +0.0013 d2b 0.10 air space r3b +35.96 +0.0173 L2b (d3b 3.80 1.6254 56.6 r4b +641.50 -0.0009 d4 15.51 air space (variable) r5 +11342.00 +0.0001 L3 (d5 1.00 1.6228 60.0 r6 +19.23 -0.0323 d6 3.70 air space r7a -43.87 -0.0185 L4a (d7a 2.40 1.8126 25.2 r7b -20.01 +0.0094 L4b (d7b 1.00 1.6228 60.0 r8b +79.77 -0.0078 d8 7.33 air space (variable) r9 -14.20 -0.0360 L5 (d9 1.00 1.5120 64.0 r10 -31.49 +0.0162 d10 4.17 air space (variable) r11 +60.03 +0.0104 L6 (d11 2.40 1.6250 52.8 r12 -29.54 +0.0211

Claim 9

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitude of their refractive indices ne and Abbe numbers Nu e, and the surface power Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 +184.30 +0.0042 L1 (d1 1.80 1.7917 25.8 r2 +37.45 -0.0211 d2 2.50 air space r2a +44.10 +0.0140 L2a (d2a 5.00 1.6176 50.8r3a -401.00 +0.0015d2b 0.10 air space r3b +37.18+0.0166L2b (d3b 5.40 1.6176 50.8 r4b -550.50 +0.0011 d4 15.44 air space (variable) r5 +477.50 +0.0013 L3 (d5 1.00 1.6228 60.0 r6 +18.46 -0.0337 d6 3.70 air space r7a -43.87 -0.0185 L4a (d7a 2.90 1.8126 25.2 r7b -19.00 +0.0099 L4b (d7b 1.50 1.6228 60.0 r8b +67.27 -0.0092 d8 9.01 air space (variable) r9 -13.50 -0.0379 L5 (d9 1.00 1.5120 64.0 r10 -30.31 +0.0168 d10 5.85 air space (variable) r11 +57.44 +0.0099 L6 (d11 2.40 1.5712 55.8 r12 -27.65 +0.0206

Claim 10

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitude of their refractive indices ne and Abbe numbers Nu e, and the surface power Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 +184.30 +0.0042 L1 (d1 1.80 1.7917 25.8 r2 +37.45 -0.0211 d2 2.50 air space r2a +44.10 +0.0140 L2a (d2a 5.00 1.6176 50.8r3a -401.00 +0.0015d2b 0.10 air space r3b +37.18+0.0166L2b (d3b 5.40 1.6176 50.8 r4b -550.50 +0.0011 d4 15.44 air space (variable) r5 +477.50 +0.0013 L3 (d5 1.00 1.6228 60.0 r6 +18.46 -0.0337 d6 3.70 air space r7a -43.87 -0.0185 L4a (d7a 2.90 1.8126 25.2 r7b -19.00 +0.0099 L4b (d7b 1.50 1.6228 60.0 r8b +67.27 -0.0092 d8 9.01 air space (variable) r9 -13.50 -0.0379 L5 (d9 1.00 1.5120 64.0 r10 -30.31 +0.0168 d10 5.85 air space (variable) r11 +57.44 +0.0099 L6 (d11 2.40 1.5712 55.8 r12 -27.65 +0.0206

Claim 11

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b and a positive fourth lens L2c following said positive second lens L2a, said second negative lens member being a doublet composed of a negative lens L4a and a positive lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said positive fourth lens L2c, said first negative lens member L3, said negative lens L4a, said positive lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 -153.40 -0.0050 L1 (d1 1.80 1.7684 26.7 r2 +91.53 -0.0083 d2 1.80 air space r2a +111.98 +0.0055 L2a (d2a 4.40 1.6228 60.0 r3a -159.60 +0.0039 d2b 0.10 air space r3b +132.70 +0.0047 L2b (d3b 4.40 1.6255 57.7 r4b -132.70 +0.0047 d3c 0.10 air space r4c +37.18 +0.0167 L2c (d4c 4.65 1.6228 60.0 r5c +102.54 -0.0060 d4 15.87 air space (variable) r5 +150.08 +0.0047 L3 (d5 1.00 1.7161 53.6 r6 +16.28 -0.0439 d6 3.70 air space r7a -60.03 -0.0107 L4a (d7a 1.50 1.6430 59.8 r7b +17.16 +0.0098 L4b (d7b 3.55 1.8126 25.2 r8b +62.14 -0.0130 d8 10.23 air space (variable) r9 -14.55 -0.0345 L5 (d9 1.00 1.5020 61.2 r10 -41.81 +0.0120 d10 8.50 air space (variable) r11 +56.91 +0.0109 L6 (d11 2.40 1.6203 54.8 r12 -32.91 +0.0188

Claim 12

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b and a positive fourth lens L2c following said positive second lens L2a, said second negative lens member being a doublet composed of a negative lens L4a and a positive lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said positive fourth lens L2c, said first negative lens member L3, said negative lens L4a, said positive lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 -153.40 -0.0050 L1 (d1 1.80 1.7684 26.7 r2 +91.53 -0.0083 d2 1.80 air space r2a +111.98 +0.0055 L2a (d2a 4.40 1.6228 60.0 r3a -159.60 +0.0039 d2b 0.10 air space r3b +132.70 +0.0047 L2b (d3b 4.40 1.6255 57.7 r4b -132.70 +0.0047 d3c 0.10 air space r4c +37.18 +0.0167 L2c (d4c 4.65 1.6228 60.0 r5c +102.54 -0.0060 d4 15.87 air space (variable) r5 +150.08 +0.0047 L3 (d5 1.00 1.7161 53.6 r6 +16.28 -0.0439 d6 3.70 air space r7a -60.03 -0.0107 L4a (d7a 1.50 1.6430 59.8 r7b +17.16 +0.0098 L4b (d7b 3.55 1.8126 25.2 r8b +62.14 -0.0130 d8 10.23 air space (variable) r9 -14.55 -0.0345 L5 (d9 1.00 1.5020 61.2 r10 -41.81 +0.0120 d10 8.50 air space (variable) r11 +56.91 +0.0109 L6 (d11 2.40 1.6203 54.8 r12 -32.91 +0.0188

Claim 13

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b and a positive fourth lens L2c following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive lens L2a, said positive third lens L2b, said positive fourth lens L2c, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separationsr1 -155.50 -0.0048 L1 (d1 1.80 1.7616 27.3 r2 +92.16 -0.0082 d2 1.60 air space r2a +116.70 +0.0053 L2a (d2a 4.80 1.6228 60.0 r3a -150.82 +0.0041 d2b 0.10 air space r3b +113.50+0.0054L2b (d3b 4.70 1.6228 60.0 r4b -163.85 +0.0038 d3c 0.10 air space r4c +37.18 +0.0167 L2c (d4c 4.65 1.6228 60.0 r5c +102.54 -0.0060 d4 17.66 air space (variable) r5 +150.82 +0.0046 L3 (d5 1.00 1.6940 54.4 r6 +17.29 -0.0401 d6 3.70 air space r7a -88.36 -0.0091 L4a (d7a 3.05 1.8126 25.2 r7b -19.64 +0.0086 L4b (d7b 1.00 1.6430 59.8 r8 +29.13 -0.0220 d8 10.75 air space (variable) r9 -12.73 -0.0392 L5 (d9 1.00 1.4995 66.7 r10 -35.96 +0.0138 d10 8.60 air space (variable) r11 +63.02 +0.0098 L6 (d11 2.40 1.6203 54.8 r12 -28.09 +0.0220

Claim 14

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b and a positive fourth lens L2c following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive lens L2a, said positive third lens L2b, said positive fourth lens L2c, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separationsr1 -155.50 -0.0048 L1 (d1 1.80 1.7616 27.3 r2 +92.16 -0.0082 d2 1.60 air space r2a +116.70 +0.0053 L2a (d2a 4.80 1.6228 60.0 r3a -150.82 +0.0041 d2b 0.10 air space r3b +113.50+0.0054L2b (d3b 4.70 1.6228 60.0 r4b -163.85 +0.0038 d3c 0.10 air space r4c +37.18 +0.0167 L2c (d4c 4.65 1.6228 60.0 r5c +102.54 -0.0060 d4 17.66 air space (variable) r5 +150.82 +0.0046 L3 (d5 1.00 1.6940 54.4 r6 +17.29 -0.0401 d6 3.70 air space r7a -88.36 -0.0091 L4a (d7a 3.05 1.8126 25.2 r7b -19.64 +0.0086 L4b (d7b 1.00 1.6430 59.8 r8 +29.13 -0.0220 d8 10.75 air space (variable) r9 -12.73 -0.0392 L5 (d9 1.00 1.4995 66.7 r10 -35.96 +0.0138 d10 8.60 air space (variable) r11 +63.02 +0.0098 L6 (d11 2.40 1.6203 54.8 r12 -28.09 +0.0220

Claim 15

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b and a positive fourth lens L2c following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said positive fourth lens L2c, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 -137.38 -0.0055 L1 (d1 2.00 1.7616 27.3 r2 +110.25 -0.0069 d2 1.80 air space r2a +188.90 +0.0033 L2a (d2a 6.85 1.6255 57.7 r3a -126.60 +0.0049 d2b 0.10 air space r3b +94.06 +0.0066 L2b (d3b 7.20 1.6228 60.0 r4b -257.20 +0.0024 d3c 0.10 air space r4c +48.02 +0.0129 L2c (d4c 6.75 1.6228 60.0 r5c +212.40 -0.0029 d4 18.56 air space (variable) r5 +496.40 +0.0013L3 (d5 1.00 1.6940 54.4 r6 +22.75 -0.0305 d6 4.50 air space r7a -137.60 -0.0059 L4a (d7a 5.00 1.8126 25.2 r7b -21.05 +0.0080 L4b (d7b 1.00 1.6430 59.8 r8b +23.27 -0.0277 d8 11.87 air space (variable) r9 -14.74 -0.0331 L5 (d9 1.00 1.4891 70.2 r10 -56.91 +0.0085 d10 13.58 air space (variable) r11 +46.49 +0.0133 L6 (d11 2.40 1.6203 54.8 r12 -44.43 +0.0139

Claim 16

A varifocal objective system comprising a basic multilens objective and a varifocal front attachment for said objective, said attachment being composed of a substantially fixed positive first component, an axially movable negative second component, an axially movable negative third component and a fixed positive fourth component; said first component consisting of a negative first lens followed by at least one positive second lens; said second component consisting of a first and a negative second lens member air-spaced from each other; said third component being a third negative lens member; said fourth component being a positive lens member; said first component including a positive third lens L2b and a positive fourth lens L2c following said positive second lens L2a, said second negative lens member being a doublet composed of a positive lens L4a and a negative lens L4b, the relative numerical values of the radii r1 - r12 and of the thicknesses and separations d1 - d11 of said front lens L1, said positive second lens L2a, said positive third lens L2b, said positive fourth lens L2c, said first negative lens member L3, said positive lens L4a, said negative lens L4b, said third negative lens member L5 and said positive lens member L6, the magnitudes of their refractive indices ne and Abbe numbers Nu e, and the surface powers Delta n/r thereof being substantially as given in the following Table: Lenses Radii Thicknesses ne Nu e Delta n/r and separations r1 -137.38 -0.0055 L1 (d1 2.00 1.7616 27.3 r2 +110.25 -0.0069 d2 1.80 air space r2a +188.90 +0.0033 L2a (d2a 6.85 1.6255 57.7 r3a -126.60 +0.0049 d2b 0.10 air space r3b +94.06 +0.0066 L2b (d3b 7.20 1.6228 60.0 r4b -257.20 +0.0024 d3c 0.10 air space r4c +48.02 +0.0129 L2c (d4c 6.75 1.6228 60.0 r5c +212.40 -0.0029 d4 18.56 air space (variable) r5 +496.40 +0.0013L3 (d5 1.00 1.6940 54.4 r6 +22.75 -0.0305 d6 4.50 air space r7a -137.60 -0.0059 L4a (d7a 5.00 1.8126 25.2 r7b -21.05 +0.0080 L4b (d7b 1.00 1.6430 59.8 r8b +23.27 -0.0277 d8 11.87 air space (variable) r9 -14.74 -0.0331 L5 (d9 1.00 1.4891 70.2 r10 -56.91 +0.0085 d10 13.58 air space (variable) r11 +46.49 +0.0133 L6 (d11 2.40 1.6203 54.8 r12 -44.43 +0.0139