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: 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: 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: 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: 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: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ndLZ+(0.01425×?dLZ)<2.12, and 0.702<?gFLZ+(0.00316×?dL=), where ndL: a refractive index of the lens with reference to d-line, ?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, vdLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where vdLZ: 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, 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.