Large aperture extended range zoom lens

An optical system for a variable focal length lens of large effective aperture, which is focusable over an extended range, having substantially the following specification:

• ______________________________________ SYSTEM EFL HALF ANGLE OF FIELD at W/A = 7.61mm (.2997 in.) 25.35.degree. at T/P = 56.98mm (2.2433 in.) 3.31.degree. at MID = 25.67mm (1.0105 in.) 7.58.degree. ______________________________________ LENS RADII (mm.) THICKNESS (mm.) ______________________________________ 1 R.sub.1 = 240.7589 T.sub.1 = 1.6510 R.sub.2 = -51.1988 2 R.sub.3 = 51.1988 T.sub.2 = 12.7000 R.sub.4 = 153.6954 3 R.sub.5 = 43.6880 T.sub.3 = 7.7978 R.sub.6 = -139.7000 4 R.sub.7 = 71.7550 T.sub.4 = .8128 R.sub.8 = -16.5100 5 R.sub.9 = -24.0030 T.sub.5 = .8382 R.sub.10 = -19.1008 6 R.sub.11 = 19.1008 T.sub.6 = 3.5052 R.sub.12 = -59.9948 7 R.sub.13 = 58.9280 T.sub.7 = .8890 R.sub.14 = -21.7424 8 R.sub.15 = 21.7424 T.sub.8 = 5.6388 R.sub.16 = 30.2260 9 R.sub.17 = 22.7203 T.sub.9 = 3.1496 R.sub.18 = -93.1672 10 R.sub.19 = -45.5168 T.sub.10 = .7112 R.sub.20 = -12.8016 11 R.sub.21 = 14.6431 T.sub.11 = 2.0574 R.sub.22 = -27.0256 12 R.sub.23 = 18.0848 T.sub.12 = 3.6576 R.sub.24 = 32.8168 13 R.sub.25 = -21.9202 T.sub.13 = .7112 R.sub.26 = -16.8656 14 R.sub.27 = 61.2140 T.sub.14 = 4.3180 R.sub.28 = -14.5288 15 R.sub.29 = 14.5288 T.sub.15 = 3.2512 R.sub.30 = 26.9494 16 R.sub.31 = 14.7320 T.sub.16 = 2.5654 R.sub.32 = -463.9259 ______________________________________ LENS RADII (mm.) SPACINGS (mm) N.sub.D V ______________________________________ 1 R.sub.1 = 240.7589 1.755 27.6 R.sub.2 = -51.1988 S.sub.1 = 0 2 R.sub.3 = 51.1988 1.620 60.4 - R.sub.4 = 153.6954 S.sub.2 = .1016 3 R.sub.5 = 43.6880 1.651 55.9 R.sub.6 = -139.7000 S.sub.3 = 4.2875 at W/A 29.5554 at T/P 22.3952 at MID 4 R.sub.7 = 71.7550 1.639 55.4 R.sub.8 = -16.5100 S.sub.4 = 6.6294 5 R.sub.9 = -24.0030 1.620 60.4 R.sub.10 = -19.1008 S.sub.5 = 0 6 R.sub.11 = 19.1008 1.785 25.8 R.sub.12 = -59.9948 S.sub.6 = 38.4048 at W/A 2.5857 at T/P 14.2570 at MID 7 R.sub.13 = 58.9280 1.805 25.4 R.sub.14 = -21.7424 S.sub.7 = 0 8 R.sub.15 = 21.7424 1.641 60.1 R.sub.16 = 30.2260 S.sub.8 = .1016 9 R.sub.17 = 22.7203 1.691 54.9 R.sub.18 = -93.1672 S.sub.9 =1.6002 at W/A 12.1514 at T/P 7.6403 at MID 10 R.sub.19 = -45.5168 1.691 54.9 R.sub.20 = -12.8016 S.sub.10 = 2.2352 11 R.sub.21 = 14.6431 1.805 25.4 R.sub.22 = -27.0256 S.sub.11 = 11.0490 ----STOP---- S.sub.12 = 3.5560 12 R.sub.23 = 18.0848 1.744 44.8 R.sub.24 = 32.8168 S.sub.13 = 1.6002 13 R.sub.25 = -21.9202 1.805 25.4 R.sub.26 = -16.8656 S.sub.14 = .7336 14 R.sub.27 = 61.2140 1.805 25.4 R.sub.28 = -14.5288 S.sub.15 = 0 15 R.sub.29 = 14.5288 1.744 44.8 R.sub.30 = 26.9494 S.sub.16 = .1270 16 R.sub.31 = 14.7320 1.734 51.7 R.sub.32 = -463.9259 S.sub.17 = 11.4529 ______________________________________
• wherein the first column lists the lens elements numerically starting at the ray entrance side of the system;
• the second column lists the respective base radii R.sub.1 to R.sub.32 ;
• the third column lists the thicknesses T.sub.1 -T.sub.16 of the respective elements;
• the fourth column lists the axial spacings S.sub.1 to S.sub.17 between the respective elements, and stop, and the image plane;
• and the fifth and sixth columns respectively list the index of refraction for the Sodium D line N.sub.D and the dispersive index V of the optical materials of the respective elements.