Abstract: An optical system (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. ?020<?F1/?F2<0.

Abstract: An optical system (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. ?020<?F1/?F2<0.

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: 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 comprises, in order from an object side, a front group having positive refractive power and a rear group. Upon carrying out focusing, the front group is moved along the optical axis. A predetermined conditional expression is satisfied. Thus, an optical system having a superb optical performance being able to correct superbly various aberrations and being suitable to be used with an imaging device having highly increased number of pixels, an optical equipment equipped therewith and a manufacturing method for the optical system are provided.

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 (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. ?020<?F1/?F2<0.

Abstract: An optical system (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. ?020<?F1/?F2<0.

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 (ZL(1)) comprises a plurality of lens groups including a first focusing lens group (G2) and a second focusing lens group (G4) that are disposed side by side on an optical axis, and the second focusing lens group (G4) is disposed at a position closer to an image surface than the first focusing lens group (G2). The first focusing lens group (G2) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G4) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL(1)) satisfies the following conditional expression. ?020<?F1/?F2<0.

Abstract: A variable magnification optical system which comprises, in order from an object side, a first lens group having negative refractive power, a second lens group having positive refractive power and a third lens group; upon varying magnification, distances between the neighboring respective lens groups being varied; upon focusing, the first lens group and the second lens group being moved along the optical axis; and predetermined conditional expression(s) being satisfied, whereby the variable magnification optical system is made in small in size, and can correct superbly various aberrations.

Abstract: An optical system comprises, in order from an object side, a front group having positive refractive power end a rear group. Upon carrying out focusing, the front group is moved along the optical axis. A predetermined conditional expression is satisfied. Thus, an optical system having a superb optical performance being able to correct superbly various aberrations and being suitable to be used with an imaging device having highly increased number of pixels, an optical equipment equipped therewith and a manufacturing method for the optical system are provided.

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.