Retrofocus type ultra-wide angle lens

Claim 2

A retrofocus type ultra-wide angle lens system comprising 13 air-spaced elements in four groups, said four groups including, as viewed from the object side of the system, a first group consisting of two dIvergent meniscus elements and a convergent meniscus element, a second group consisting of three divergent meniscus elements and a convergent cemented component, a third group consisting of a divergent meniscus element and a positive cemented component, said third group being immediately followed by a diaphragm, and a fourth group consisting of a convergent element, a divergent element, a convergent element and a cemented convergent component.

Claim 3

A retrofocus type ultra-wide angle lens system comprising 13 air-spaced elements in four groups, said four groups including, as viewed from the object side of the system, a first group consisting of two divergent meniscus elements and a convergent meniscus element, a second group consisting of three divergent meniscus elements and a convergent cemented component, a third group consisting of a divergent meniscus element and a positive cemented component, said third group being immediately followed by a diaphragm, and a fourth group consisting of a convergent element, a divergent element, a convergent meniscus element and a cemented component, said lens system having the following characteristics: Focal length f 13.2mm, Relative Aperture F/8, Angle of view 118* R1 57.2 d1 3.9 n1 1.77279 gamma d1 49.5 R2 43.0 d2 11.9 R3 51.0 d3 3.0 n2 1.7335 gamma d2 51.0 R4 37.5 d4 9.3 R5 48.2 d5 13.5 n3 1.732 gamma d3 53.7 R6 190.0 d6 0.1 R7 28.5 d7 1.2 n4 1.7335 gamma d4 51.0 R8 17.6 d8 3.3 R9 22.5 d9 1.0 n5 1.7320 gamma d5 53.7 R10 13.2 d10 3.0 R11 17.6 d11 1.0 n6 1.732 gamma d6 53.7 R12 12.0 d12 6.5 R0 Infinity d0 1.2 n0 1.51743 Filter R0 Infinity d0 0.5 R13 350.0 d13 3.0 n7 1.83739 gamma d7 43.5 R14 12.08 d14 12.3 n8 1.54072 gamma d8 47.2 R15 - 15.8 d15 0.1 R16 17.0 d16 0.8 n9 1.6968 gamma d9 55.6 R17 7.45 d17 1.7 R18 11.9 d18 2.8 n10 1.59507 gamma d10 35.6 R19 - 9.0 d19 0.9 n11 1.60311 gamma d11 60.7 R20 Infinity d20 1.6 R21 Infinity d21 4.1 n12 1.59507 gamma d12 35.6 R22 - 10.5 d22 0.6 R23 - 13.1 d23 1.5 n13 1.86074 gamma d13 23.1 R24 35.4 d24 0.65 R25 - 41.0 d25 2.2 n14 1.44628 gamma d14 67.2 R26 - 9.6 d26 0.1 R27 900.0 d27 0.8 n15 1.8663 gamma d15 37.9 R28 30.7 d28 5.7 n16 1.48749 gamma d16 70.0 R29 - 14.901 B.f. 37.517 wherein, R subscript denotes the radius of curvature of the surface of each element; d subscript denotes the thickness of each element and the air space between adjacent elements; n subscripts denotes the refractive index of each element; and gamma d subscripts denotes the Abbe number of each element.

Claim 4

A retrofocus type ultra-wide angle lens system comprising 13 air-spaced elements in four groups, said four groups including, as viewed from the object side of the system, a first group consisting of two divergent meniscus elements and a convergent meniscus element, a second group consisting of three divergent meniscus elements and a convergent cemented component, a third group consisting of a divergent meniscus element and a positive cemented component, said third group being immediately followed by a diaphragm, and a fourth group consisting of a convergent element, a divergent element, a convergent meniscus element and a cemented component, said lens system having the following characteristics: Focal length f 13.2mm, Relative Aperture F/8, Angle of view 118* R1 57.2 d1 3.9 n1 1.77279 gamma d1 49.5 R2 43.0 d2 11.9 R3 51.0 d3 3.0 n2 1.7335 gamma d2 51.0 R4 37.5 d4 9.3 R5 48.2 d5 13.5 n3 1.732 gamma d3 53.7 R6 190.0 d6 0.1 R7 28.5 d7 1.2 n4 1.7335 gamma d4 51.0 R8 17.6 d8 3.3 R9 22.5 d9 1.0 n5 1.7320 gamma d5 53.7 R10 13.2 d10 3.0 R11 17.6 d11 1.0 n6 1.732 gamma d6 53.7 R12 12.0 d12 6.5 R0 Infinity d0 1.2 n0 1.51743 Filter R0 Infinity d0 0.5 R13 350.0 d13 3.0 n7 1.83739 gamma d7 43.5 R14 12.08 d14 12.3 n8 1.54072 gamma d8 47.2 R15 - 15.8 d15 0.1 R16 17.0 d16 0.8 n9 1.6968 gamma d9 55.6 R17 7.45 d17 1.7 R18 11.9 d18 2.8 n10 1.59507 gamma d10 35.6 R19 - 9.0 d19 0.9 n11 1.60311 gamma d11 60.7 R20 Infinity d20 1.6 R21 Infinity d21 4.1 n12 1.59507 gamma d12 35.6 R22 - 10.5 d22 0.6 R23 - 13.1 d23 1.5 n13 1.86074 gamma d13 23.1 R24 35.4 d24 0.65 R25 - 41.0 d25 2.2 n14 1.44628 gamma d14 67.2 R26 - 9.6 d26 0.1 R27 900.0 d27 0.8 n15 1.8663 gamma d15 37.9 R28 30.7 d28 5.7 n16 1.48749 gamma d16 70.0 R29 - 14.901 B.f. 37.517 wherein, R subscript denotes the radius of curvature of the surface of each element; d subscript denotes the thickness of each element and the air space between adjacent elements; n subscripts denotes the refractive index of each element; and gamma d subscripts denotes the Abbe number of each element.