Abstract: A zoom optical system (ZL), comprises, in order from an object: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; a third lens group (G3) having a positive refractive power; a fourth lens group (G4) having a positive refractive power; a fifth lens group (G5); and a sixth lens group (G6). In the zoom optical system, upon zooming, a distance between the adjacent lens groups changes. The zoom optical system satisfies the following conditional expression. 1.00<Mv4/Mv3<3.00 where Mv3: an amount of movement of the third lens group upon zooming from a wide angle end state to a telephoto end state (a sign of the amount of movement toward an object is shown as +), and Mv4: an amount of movement of the fourth lens group upon zooming from the wide angle end state to the telephoto end state (the sign of the amount of movement toward an object is shown as +).

Abstract: A zoom optical system (ZL) comprises, in order from an object: a first lens group (G1) having a positive refractive power; and a second lens group (G2) having a negative refractive power, wherein upon zooming, a distance between the adjacent lens groups changes. The zoom optical system further comprises an aperture stop (S) disposed closer to an image than the second lens group (G2, and satisfies the following conditional expression: 0.10<Df/Dr<0.90 where Df: a distance to the aperture stop from a lens surface of the zoom optical system closest to an object in a wide angle end state, and Dr: a distance from the aperture stop to a lens surface of the zoom optical system closest to the image in the wide angle end state.

Abstract: This optical system (LS) has an aperture diaphragm (S) and a negative lens (L4) disposed closer to an object side than the aperture diaphragm (S) and satisfies the following conditional expression. ?0.010<ndN1?(2.015?0.0068×?dN1), 50.00<?dN1<65.00, 0.545<?gFN1, ?0.010<?gFN1?(0.6418?0.00168×?dN1). Where, ndN1 is a refractive index of the negative lens with respect to a d-line, ?dN1 is an Abbe number of the negative lens based on the d-line, and ?gFN1 is a partial dispersion ratio of the negative lens.

Abstract: An optical system (LS) has a lens (L11) that satisfies the following conditional expressions. - 0.01 < ndLZ - ( 2.015 - 0.0068 × vdLZ ) 50. < vdLZ < 65. 0.545 < ? ? gFLZ - 0.01 < ? ? gFLZ - ( 0.6418 - 0.00168 × vdLZ ) where ndLZ is the refractive index to the d line of the lens, vdLZ is the Abbe number with respect to the d line of the lens, and ?gFLZ is the partial dispersion ratio of the lens.

Abstract: An optical system (LS) has a lens (L11) that satisfies the following conditional expressions. ?0.010<ndLZ?(2.015?0.0068×?dLZ) 50.00<?dLZ<65.00 0.545<?gFLZ ?0.010<?gFLZ?(0.6418?0.00168×?dLZ) where ndLZ is the refractive index to the d line of the lens, ?dLZ is the Abbe number with respect to the d line of the lens, and ?gFLZ is the partial dispersion ratio of the lens.

Abstract: An optical system comprising, in order from an object side, a first lens group, an aperture stop, and a rear group that includes a first cemented lens comprising a positive lens and a negative lens is configured so as to satisfy the following conditional expressions: 0.350<Bf/y<0.700 1.350<TL/y<2.000 0.050<Np1?Nn1<0.400 where Bf is a back focal length in air; y is maximum image height; TL is the distance from a lens surface closest to the object side to an image plane; and Np1 and Nn1 are the refractive indices of the positive and negative lenses constituting the first cemented lens, respectively.

Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ?dLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where ?dLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ=(ngLZ?nFLZ)/(nFLZ?nCLZ). wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.

Abstract: An optical system (LS) has an aperture stop (S), and a negative lens (L73) disposed closer to the image side than the aperture stop (S) and satisfying the following conditional expressions. ?0.010<ndN2?(2.015?0.0068×?dN2), 50.00<?dN2<65.00, 0.545<?gFN2, ?0.010<?gFN2?(0.6418?0.00168×?dN2) where ndN2 is the refractive index to the d line of the negative lens, ?dN2 is the Abbe number with respect to the d line of the negative lens, and ?gFN2 is the partial dispersion ratio of the negative lens.

Abstract: A variable magnification optical system including a plurality of lens groups, which is six or more lens groups and comprises a first lens group having positive refractive power and a rear group disposed closer to an image side than the first lens group, is configured so that at varying magnification the distances between the lens groups are varied, the first lens group consists of two or fewer lenses, and both the following conditional expressions are satisfied: 8 . 0 ? 0 < f ? 1 / D ? 1 < 2 ? 7 .00 1. < M ? 1 / D ? 1 < 1 ? 2 . 0 ? 0 where f1 is the focal length of the first lens group, D1 is the thickness of the first lens group on an optical axis, and M1 is the amount of movement of the first lens group at varying magnification from a wide-angle end state to a telephoto end state.

Abstract: A variable magnification optical system including a plurality of lens groups, which is six or more lens groups and comprises a first lens group having positive refractive power and a rear group disposed closer to an image side than the first lens group, is configured so that at varying magnification the distances between the lens groups are varied, the first lens group consists of two or fewer lenses, and both the following conditional expressions are satisfied: 7.50<f1/D1<55.00??(1) 4.00<M1/D1<22.00??(2) where f1 is the focal length of the first lens group, D1 is the thickness of the first lens group on an optical axis, and M1 is the amount of movement of the first lens group at varying magnification from a wide-angle end state to a telephoto end state.

Abstract: An optical system is configured to include, in order from an object side, a first lens group, a stop, and a rear group including at least one cemented lens, and to satisfy all of the following conditional expressions: 0 . 3 ? 5 < Bf / y < 0 .70 1.35 < TL / y < 1.85 where Bf is a back focus in air-equivalent length, and y is a maximum image height. Further, an optical system is configured to include, in order from an object side, a first lens group, a stop, and a rear group having an air gap between a lens disposed closest to an image-plane side of one or more lenses included in the first lens group and the stop, and to satisfy the following conditional expression: 1.35 < TL / y < 1.85 where TL is the distance from a lens surface closest to the object side to an image plane at focusing on an object at infinity, and y is a maximum image height.

Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ndLZ+(0.01425×?dLZ)<2.12, and ?dLZ<35.0, where ndLZ: a refractive index of the lens with reference to d-line, and ?dLZ: Abbe number of the lens with reference to d-line.

Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ?dLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where ?dLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ=(ngLZ?nFLZ)/(nFLZ?nCLZ). wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.

Abstract: An optical system (LS) Includes lenses (L22,L23) satisfying the following conditional expressions, ?dLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where ?dLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ?(ngLZ?nFLZ)/(nFLZ?nCLZ). wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.

Abstract: An optical system (LS) has an aperture stop (S), and a positive lens (L4) disposed closer to the object side than the aperture stop (S). The positive lens (L4) satisfies the following conditional expressions. ?0.010<ndP1?(2.015?0.0068×?dP1) 50.00<?dP1<65.00 0.545<?gFP1 ?0.010<?gFP1?(0.6418?0.00168×?dP1) where ndP1 is the refractive index to the d line of the positive lens, ?dP1 is the Abbe number with respect to the d line of the positive lens, and ?gFP1 is the partial dispersion ratio of the positive lens.

Abstract: An optical system (LS) has an aperture stop (S), and a negative lens (L73) disposed closer to the image side than the aperture stop (S) and satisfying the following conditional expressions. ?0.010<ndN2?(2.015?0.0068×?dN2), 50.00<?dN2<65.00, 0.545<?gFN2, ?0.010<?gFN2?(0.6418?0.00168×?dN2) where ndN2 is the refractive index to the d line of the negative lens, ?dN2 is the Abbe number with respect to the d line of the negative lens, and ?gFN2 is the partial dispersion ratio of the negative lens.

Abstract: An optical system (LS) has a lens (L11) that satisfies the following conditional expressions. ?0.010<ndLZ?(2.015?0.0068×?dLZ) 50.00<?dLZ<65.00 0.545<?gFLZ ?0.010<?gFLZ?(0.6418?0.00168×?dLZ) where ndLZ is the refractive index to the d line of the lens, ?dLZ is the Abbe number with respect to the d line of the lens, and ?gFLZ is the partial dispersion ratio of the lens.

Abstract: This optical system (LS) has an aperture diaphragm (S) and a negative lens (L4) disposed closer to an object side than the aperture diaphragm (S) and satisfies the following conditional expression. ?0.010<ndN1?(2.015?0.0068×?dN1), 50.00<?dN1<65.00, 0.545<?gFN1, ?0.010<?gFN1?(0.6418?0.00168×?dN1). Where, ndN1 is a refractive index of the negative lens with respect to a d-line, vdN1 is an Abbe number of the negative lens based on the d-line, and ?gFN1 is a partial dispersion ratio of the negative lens.

Abstract: A zoom optical system (ZL), comprises, in order from an object: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; a third lens group (G3) having a positive refractive power; a fourth lens group (G4) having a positive refractive power; a fifth lens group (G5); and a sixth lens group (G6). In the zoom optical system, upon zooming, a distance between the adjacent lens groups changes. The zoom optical system satisfies the following conditional expression. 1.00<Mv4/Mv3<3.00 where Mv3: an amount of movement of the third lens group upon zooming from a wide angle end state to a telephoto end state (a sign of the amount of movement toward an object is shown as +), and Mv4: an amount of movement of the fourth lens group upon zooming from the wide angle end state to the telephoto end state (the sign of the amount of movement toward an object is shown as +).

Abstract: A zoom optical system (ZL) comprises, in order from an object: a first lens group (G1) having a positive refractive power; and a second lens group (G2) having a negative refractive power, wherein upon zooming, a distance between the adjacent lens groups changes. The zoom optical system further comprises an aperture stop (S) disposed closer to an image than the second lens group (G2, and satisfies the following conditional expression: 0.10<Df/Dr<0.90 where Df: a distance to the aperture stop from a lens surface of the zoom optical system closest to an object in a wide angle end state, and Dr: a distance from the aperture stop to a lens surface of the zoom optical system closest to the image in the wide angle end state.