Four component compact zoom lens

Claim 2

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component, a positive component, a positive cemented doublet component and a rear negative component comprising three elements, and a diaphragm mounted with the first-mentioned positive component, the total length from the vertex of the front surface of the front lens element to the focal plane being less than 1.8F s at the short focal length setting and less than F L the long focal length setting, wherein F s is the short focal length and F L is the long focal length.

Claim 3

A zoom lens as claimed in claim 1, wherein with the ratios VR of the Abbe V numbers of the elements of said positive cemented doublet greater than unity 3>VR>1.8.

Claim 4

A zoom lens as claimed in claim 1 or 2, wherein said negative component comprises front, second, and rear elements and with the ratio VR 12 of the Abbe V numbers of the front and second element greater than unity 3>VR 12 >1.3.

Claim 5

A zoom lens as claimed in claim 1, wherein the positive cemented doublet component includes a front element having a refractive index N C and a rear element having a refractive index N D and wherein 0.4>|N C -N D |>0.1.

Claim 6

A zoom lens as claimed in claim 4, wherein with the ratio VR of the Abbe V numbers of the elements of said positive cemented doublet greater than unity 3>VR>1.8 and said negative component includes front, second and rear elements and with the ratio VR 12 of the Abbe V numbers of the front and second elements greater than unity 3>VR 12 >1.3.

Claim 7

A zoom lens assembly made substantially according to the following specifications: __________________________________________________________________________ REFRACTIVE Abbe INDEX No. GROUP LENS RADIUS THICKNESS SPACING N.sub.d V.sub.d __________________________________________________________________________ S.sub.1 = ∞ R.sub.1 = -25.7439 27 A t.sub.1 = 2.500 1.71301 53.8 R.sub.2 = -99.0606 7.622 at 35.06 5.789 at 50.48 S.sub.2 = 3.266 at 72.77 1.000 at 104.56 Diaphragm FS.sub.1 = 0.200 R.sub.3 = asphere 29 B t.sub.3 = 3.800 1.80400 46.6 R.sub.4 = -50.2153 8.023 at 35.06 7.420 at 50.48 S.sub.3 = 6.221 at 72.77 5.109 at 104.56 R.sub.5 = 46.3678 C t.sub.4 = 1.500 1.84666 23.8 31 R.sub.6 = 16.5287 D t.sub.5 = 6.269 1.49783 67.0 R.sub.7 = -23.9031 8.699 at 35.06 4.353 at 50.48 S.sub.4 = 1.972 at 72.77 0.500 at 104.56 R.sub.8 = -50.4295 E t.sub.7 = 4.58 1.84666 23.8 R.sub.9 = -18.7258 FS.sub.2 = 0.100 R.sub.10 = -22.1134 33 F t.sub.9 = 1.8 1.79952 42.2 R.sub.11 = -58.7660 FS.sub.3 = 3.588 R.sub.12 = -16.8917 G t.sub.11 = 2.00 1.69100 54.7 R.sub.13 = 146.044 8.25 at 35.06 21.80 at 50.48 S.sub.5 = 39.76 at 72.77 64.20 at 104.56 __________________________________________________________________________

Claim 8

A zoom lens assembly made substantially according to the following specifications: __________________________________________________________________________ REFRACTIVE Abbe INDEX No. GROUP LENS RADIUS THICKNESS SPACING N.sub.d V.sub.d __________________________________________________________________________ S.sub.1 = ∞ R.sub.1 = -25.7439 27 A t.sub.1 = 2.500 1.71301 53.8 R.sub.2 = -99.0606 7.622 at 35.06 5.789 at 50.48 S.sub.2 = 3.266 at 72.77 1.000 at 104.56 Diaphragm FS.sub.1 = 0.200 R.sub.3 = asphere 29 B t.sub.3 = 3.800 1.80400 46.6 R.sub.4 = -50.2153 8.023 at 35.06 7.420 at 50.48 S.sub.3 = 6.221 at 72.77 5.109 at 104.56 R.sub.5 = 46.3678 C t.sub.4 = 1.500 1.84666 23.8 31 R.sub.6 = 16.5287 D t.sub.5 = 6.269 1.49783 67.0 R.sub.7 = -23.9031 8.699 at 35.06 4.353 at 50.48 S.sub.4 = 1.972 at 72.77 0.500 at 104.56 R.sub.8 = -50.4295 E t.sub.7 = 4.58 1.84666 23.8 R.sub.9 = -18.7258 FS.sub.2 = 0.100 R.sub.10 = -22.1134 33 F t.sub.9 = 1.8 1.79952 42.2 R.sub.11 = -58.7660 FS.sub.3 = 3.588 R.sub.12 = -16.8917 G t.sub.11 = 2.00 1.69100 54.7 R.sub.13 = 146.044 8.25 at 35.06 21.80 at 50.48 S.sub.5 = 39.76 at 72.77 64.20 at 104.56 __________________________________________________________________________

Claim 9

A zoom lens assembly made substantially according to the following specifications: __________________________________________________________________________ REFRACTIVE Abbe INDEX No. GROUP LENS RADIUS THICKNESS SPACING N.sub.d V.sub.d __________________________________________________________________________ S.sub.1 ' = ∞ R.sub.21 = -26.5947 27' A' t.sub.21 = 2.500 1.57958 53.7 R.sub.22 = -166.152 7.771 at 35.02 7.353 at 50.49 S.sub.2 ' = 4.816 at 72.80 1.000 at 104.79 Baffle FS.sub.21 = 0.200 R.sub.23 = asphere 29' B' t.sub.22 = 4.000 1.53172 48.8 R.sub.24 = -27.4940 FS.sub.22 = 4.600 Diaphragm 4.419 at 35.02 3.312 at 50.49 S.sub.3 ' = 2.183 at 72.80 1.563 at 104.79 R.sub.25 = 54.4437 C' t.sub.23 = 1.5 1.84666 23.8 R.sub.26 = 15.0805 31' D' t.sub.24 = 5.125 1.49783 67.0 R.sub.27 = -17.0839 6.161 at 35.02 2.723 at 50.49 S.sub.4 ' = 1.121 at 72.80 0.500 at 104.79 R.sub.28 = -40.7438 E' t.sub.25 = 5.645 1.84666 23.8 R.sub.29 = -10.5410 33' F' t.sub.26 = 3.890 1.70181 41.0 R.sub.30 = -150.263 FS.sub.23 = 3.890 R.sub.31 = -13.9956 G' t.sub.27 = 2.000 1.65016 39.2 R.sub.32 = 1438.91 7.95 at 35.02 21.46 at 50.49 S.sub.5 ' = 38.41 at 72.80 58.69 at 104.79 __________________________________________________________________________

Claim 10

A zoom lens assembly made substantially according to the following specifications: __________________________________________________________________________ REFRACTIVE Abbe INDEX No. GROUP LENS RADIUS THICKNESS SPACING N.sub.d V.sub.d __________________________________________________________________________ S.sub.1 ' = ∞ R.sub.21 = -26.5947 27' A' t.sub.21 = 2.500 1.57958 53.7 R.sub.22 = -166.152 7.771 at 35.02 7.353 at 50.49 S.sub.2 ' = 4.816 at 72.80 1.000 at 104.79 Baffle FS.sub.21 = 0.200 R.sub.23 = asphere 29' B' t.sub.22 = 4.000 1.53172 48.8 R.sub.24 = -27.4940 FS.sub.22 = 4.600 Diaphragm 4.419 at 35.02 3.312 at 50.49 S.sub.3 ' = 2.183 at 72.80 1.563 at 104.79 R.sub.25 = 54.4437 C' t.sub.23 = 1.5 1.84666 23.8 R.sub.26 = 15.0805 31' D' t.sub.24 = 5.125 1.49783 67.0 R.sub.27 = -17.0839 6.161 at 35.02 2.723 at 50.49 S.sub.4 ' = 1.121 at 72.80 0.500 at 104.79 R.sub.28 = -40.7438 E' t.sub.25 = 5.645 1.84666 23.8 R.sub.29 = -10.5410 33' F' t.sub.26 = 3.890 1.70181 41.0 R.sub.30 = -150.263 FS.sub.23 = 3.890 R.sub.31 = -13.9956 G' t.sub.27 = 2.000 1.65016 39.2 R.sub.32 = 1438.91 7.95 at 35.02 21.46 at 50.49 S.sub.5 ' = 38.41 at 72.80 58.69 at 104.79 __________________________________________________________________________

Claim 11

A zoom lens assembly made substantially according to the following specifications: __________________________________________________________________________ REFRACTIVE Abbe INDEX No. GROUP LENS RADIUS THICKNESS SPACING N.sub.d V.sub.d __________________________________________________________________________ S.sub.1 " = ∞ R.sub.41 = -28.9346 27" A" t.sub.41 = 2.5 1.58913 61.3 R.sub.42 = -170.955 8.701 at 35.01 8.040 at 50.48 S.sub.2 " = 4.990 at 72.79 0.800 at 104.88 R.sub.43 = ashpere .sup. B.sub.a " t.sub.42 = 1.500 1.59044 30.9 R.sub.44 = 32.5160 29" FS.sub.31 = 0.200 R.sub.45 = 26.4507 .sup. B.sub.b " t.sub.43 = 4.400 1.54072 47.2 R.sub.46 = -32.5160 FS.sub.32 = 3.500 Diaphragm 3.759 at 35.01 2.433 at 50.48 S.sub.3 " = 1.226 at 72.79 0.612 at 104.88 R.sub.47 = 45.5291 C" t.sub.44 = 1.500 1.84666 23.8 31" R.sub.48 = 14.1057 D" t.sub.45 = 5.234 1.49783 67.0 R.sub.50 = -18.6600 6.187 at 35.01 2.786 at 50.48 S.sub.4 " = 1.204 at 72.79 0.500 at 104.88 R.sub.51 = -49.1546 E" t.sub.46 = 5.330 1.84666 23.8 R.sub.52 = -10.7888 33" F" t.sub.47 = 1.800 1.70181 41.0 R.sub.54 = -220.343 FS.sub.33 = 3.540 R.sub.55 = -14.5565 G" t.sub.48 = 2.000 1.65016 39.2 R.sub.56 = 201.766 8.79 at 35.01 22.61 at 50.48 S.sub.5 " = 39.69 at 72.79 60.38 at 104.88 __________________________________________________________________________

Claim 12

A zoom lens assembly made substantially according to the following specifications: __________________________________________________________________________ REFRACTIVE Abbe INDEX No. GROUP LENS RADIUS THICKNESS SPACING N.sub.d V.sub.d __________________________________________________________________________ S.sub.1 " = ∞ R.sub.41 = -28.9346 27" A" t.sub.41 = 2.5 1.58913 61.3 R.sub.42 = -170.955 8.701 at 35.01 8.040 at 50.48 S.sub.2 " = 4.990 at 72.79 0.800 at 104.88 R.sub.43 = ashpere .sup. B.sub.a " t.sub.42 = 1.500 1.59044 30.9 R.sub.44 = 32.5160 29" FS.sub.31 = 0.200 R.sub.45 = 26.4507 .sup. B.sub.b " t.sub.43 = 4.400 1.54072 47.2 R.sub.46 = -32.5160 FS.sub.32 = 3.500 Diaphragm 3.759 at 35.01 2.433 at 50.48 S.sub.3 " = 1.226 at 72.79 0.612 at 104.88 R.sub.47 = 45.5291 C" t.sub.44 = 1.500 1.84666 23.8 31" R.sub.48 = 14.1057 D" t.sub.45 = 5.234 1.49783 67.0 R.sub.50 = -18.6600 6.187 at 35.01 2.786 at 50.48 S.sub.4 " = 1.204 at 72.79 0.500 at 104.88 R.sub.51 = -49.1546 E" t.sub.46 = 5.330 1.84666 23.8 R.sub.52 = -10.7888 33" F" t.sub.47 = 1.800 1.70181 41.0 R.sub.54 = -220.343 FS.sub.33 = 3.540 R.sub.55 = -14.5565 G" t.sub.48 = 2.000 1.65016 39.2 R.sub.56 = 201.766 8.79 at 35.01 22.61 at 50.48 S.sub.5 " = 39.69 at 72.79 60.38 at 104.88 __________________________________________________________________________

Claim 13

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein: -1.86F s <F 1 <-1.27F s 0.87F s >F 2 >0.69F s 1.74F s >F 3 >1.16F s -0.79F s <F 4 <-0.50F s .

Claim 14

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein: -1.86F s <F 1 <-1.27F s 0.87F s >F 2 >0.69F s 1.74F s >F 3 >1.16F s -0.79F s <F 4 <-0.50F s .

Claim 15

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein: -1.55F s <F 1 <-1.27F s 0.87F s >F 2 >0.17F s 1.74F s >F 3 >1.42F s -0.79F s <F 4 <-0.71F s .

Claim 16

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein: -1.55F s <F 1 <-1.27F s 0.87F s >F 2 >0.17F s 1.74F s >F 3 >1.42F s -0.79F s <F 4 <-0.71F s .

Claim 17

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein:

Claim 18

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein:

Claim 19

-1. 72F s <F 1 <-1.40F s 0.85F s >F 2 >0.69F s 1.29F s >F 3 >1.16F s -0.61F s <F 4 <-0.50F s .

Claim 20

-1. 72F s <F 1 <-1.40F s 0.85F s >F 2 >0.69F s 1.29F s >F 3 >1.16F s -0.61F s <F 4 <-0.50F s .

Claim 21

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein: -1.86F s <F 1 <-1.52F s 0.87F s >F 2 >0.71F s 1.51F s >F 3 >1.23F s -0.63F s <F 4 <-0.51F s .

Claim 22

A zoom lens comprising four components each movable axially to vary the focal length through a range of at least 2.5:1, including a front negative component having a focal length F 1 , a positive component having a focal length F 2 , a positive cemented doublet component having a focal length F 3 and a negative component comprising three elements having a focal length F 4 , the shortest focal length being F s , wherein: -1.86F s <F 1 <-1.52F s 0.87F s >F 2 >0.71F s 1.51F s >F 3 >1.23F s -0.63F s <F 4 <-0.51F s .