Abstract: A zoom optical system comprises, in order from an object: a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; and a subsequent group (GR) including at least one lens group. Upon zooming, distances between the first lens group (G1) and the second lens group (G2) and between the second lens group (G2) and the subsequent group (GR) change. The subsequent group (GR) comprises a focusing group (Gfc) having negative refractive power for focusing. The first lens group (G1) comprises a 1-1st lens that has positive refractive power and is disposed closest to the object. A following conditional expression is satisfied: 0.2 < f ? 1 / fR < 0 . 8 ? 5 where, f1 denotes a focal length of the first lens group, and fR denotes a focal length of a lens component, in the subsequent group, closest to an image surface.

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 first intermediate lens group (GM1) having a positive refractive power, a second intermediate lens group (GM2) having a positive or negative refractive power, and a last lens group (GLT) having a positive or negative refractive power. Upon zooming, distances between adjacent lens groups change. The second intermediate lens group (GM2) includes a focusing lens group that moves upon focusing. The first lens group (G1) includes, a 1-1st lens having a negative refractive power and a 1-2nd lens having a positive refractive power. The zoom optical system satisfies a following conditional expression. 0.01 < dP ? 1 / f ? 1 < 0.075 where dP1: a sum of a center thickness of the 1-1st lens and a center thickness of the 1-2nd lens, and f1: a focal length of the first lens group (G1).

Abstract: An optical system (OL) includes a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, disposed in order from an object along an optical axis, and upon focusing, the second lens group and the fourth lens group move along the optical axis, and the following conditional expression is satisfied: 0. 5 ? 0 < f ? 1 / f ? 3 < 2 . 0 ? 0 where f1: a focal length of the first lens group f3: a focal length of the third lens group.

Abstract: A variable magnification optical system comprising a plurality of lens groups and, upon varying a magnification, distances between respective lens groups in the plurality of lens groups being varied. The plurality of lens groups comprises an object side focusing lens group which is moved upon carrying out focusing and at least one image side focusing lens group disposed in a more image side than the object side focusing lens group and moved with a trajectory differing from that of the object side focusing lens group, upon carrying out focusing. The predetermined conditional expressions are satisfied. Thus, variations in aberrations upon varying magnification from the wide angle end state to the telephoto end state as well as variations in aberrations upon carrying out focusing from an infinite distance object to a close distance object can be suppressed superbly.

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 first intermediate lens group (GM1) having a positive refractive power, a second intermediate lens group (Gd2) having a positive or negative refractive power, and a last lens group (GLT) having a positive or negative refractive power. Upon zooming, distances between adjacent lens groups change. The second intermediate lens group (GM2) includes a focusing lens group that moves upon focusing. The first lens group (G1) includes, a 1-1st lens having a negative refractive power and a 1-2nd lens having a positive refractive power. The zoom optical system satisfies a following conditional expression. 0.010<dP1/f1<0.075 where dP1: a sum of a center thickness of the 1-1st lens and a center thickness of the 1-2nd lens, and f1: a focal length of the first lens group (G1).

Abstract: A variable magnification optical system comprising a plurality of lens groups and, upon varying a magnification, distances between respective lens groups in the plurality of lens groups being varied. The plurality of lens groups comprises an object side focusing lens group which is moved upon carrying out focusing and at least one image side focusing lens group disposed in a more image side than the object side focusing lens group and moved with a trajectory differing from that of the object side focusing lens group, upon carrying out focusing. The predetermined conditional expressions are satisfied. Thus, variations in aberrations upon varying magnification from the wide angle end state to the telephoto end state as well as variations in aberrations upon carrying out focusing from an infinite distance object to a close distance object can be suppressed superbly.

Abstract: A variable magnification optical system including, in order from an object side, a first lens group having negative refractive power and a subsequent lens group including a plurality of lens groups is configured so that the subsequent lens group includes second and third lens groups in order from the object side, both having positive refractive power, that at varying magnification, the first lens group is fixed with respect to an image plane, and the spacings between adjacent lens groups are varied, and that the following conditional expression is satisfied: 1. < f ? 2 / f ? 3 < 5 . 0 ? 0 where f2 and f3 are the focal lengths of the second and third lens groups, respectively.

Abstract: An optical system (OL) comprises a front group (GA), an intermediate group (GM), and a rear group (GR). The intermediate group (GM) comprises a first focusing lens group (GF1) and a second focusing lens group (GF2). During focusing, the first focusing lens group (GF1) and the second focusing lens group (GF2) move along the optical axis on different trajectories from each other. The front group (GA) and the rear group (GR) are fixed in relation to an image plane (I). The rear group (GR) has a negative lens disposed closest to the image plane. The following conditional formula is satisfied. 0.01 < fF ? 2 / fF ? 1 < 10. ; 0.5 < Y / Bf < 5. . where, fF1: the focal length of the first focusing lens group (GF1), fF2: the focal length of the second focusing lens group (GF2), Y: the image height of the optical system (OL), Bf: the back focus of the optical system (OL).

Abstract: A variable magnification optical system including, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a subsequent lens group including a plurality of lens groups is configured so that at varying magnification, the first and third lens groups are fixed with respect to an image plane, and the spacings between adjacent lens groups are varied, and that the following conditional expression is satisfied: 0.24<(TL/f1)/(ft/fw)<0.55 where TL is the distance from a lens surface closest to the object side to the image plane, f1 is the focal length of the first lens group, ft is the focal length of the variable magnification optical system in a telephoto end state, and fw is the focal length of the variable magnification optical system in a wide-angle end state.

Abstract: A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M1 lens group (GM1) having a negative refractive power; an M2 lens group (GM2) having a positive refractive power; and an RN lens group (GRN) having a negative refractive power, wherein upon zooming, distances between the front lens group and the M1 lens group, between the M1 lens group and the M2 lens group, and between the M2 lens group and the RN lens group change, upon focusing from an infinite distant object to a short distant object, the RN lens group moves, the RN lens group comprises at least one lens having a positive refractive power, and at least one lens having a negative refractive power, and following conditional expressions are satisfied, 2.70<fFP/(?fFN)<4.50, 0.25<(?fF)/f1<0.

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 and a succeeding lens group (GR). In the zoom optical system, upon zooming, distances between adjacent lens groups change, and the succeeding lens group (GR) includes a plurality of focusing lens groups that have positive refractive powers and move upon focusing.

Abstract: A variable magnification optical system comprising, in order from an object side, a first lens group having negative refractive power, a first intermediate lens group having positive refractive power, a second intermediate lens group and a rear lens group; upon varying a magnification from a wide angle end state to a telephoto end state, the first lens group being moved along the optical axis, a distance between the first lens group and the first intermediate lens group being varied, a distance between the first intermediate lens group and the second intermediate lens group being varied, and a distance between the second intermediate lens group and the rear lens group being varied; the rear lens group comprising at least one focusing lens group which is moved upon carrying out focusing from an infinitely distant object to a closely distant object; and predetermined conditional expressions being satisfied, thereby the focusing lens group(s) being reduced in weight.

Abstract: A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M1 lens group (GM1) having a negative refractive power; an M2 lens group (GM2) having a positive refractive power; and an RN lens group (GRN) having a negative refractive power, wherein upon zooming, distances between the front lens group and the M1 lens group, between the M1 lens group and the M2 lens group, and between the M2 lens group and the RN lens group change, upon focusing from an infinite distant object to a short distant object, the RN lens group moves, the RN lens group comprises at least one lens having a positive refractive power, and at least one lens having a negative refractive power, and following conditional expressions are satisfied, 2.70<fFP/(?fFN)<4.50, 0.25<(?fF)/f1<0.

Abstract: A variable power optical system (ZL (1)) includes a plurality of lens groups (G1-G7). During variable magnification, an interval between adjacent lens groups changes. The plurality of lens groups include: a first focusing lens group (G5) that moves during focusing; and a second focusing lens group (G6) that is disposed more toward an imaging surface side than the first focusing lens group and that moves along a different trajectory than the first focusing lens group during focusing. The first focusing lens group and the second focusing lens group both have a negative refractive power. The first focusing lens group or the second focusing lens group includes at least one lens having a positive refractive power, and is configured so as to satisfy the following condition: 1.40<EFP/(?fFN)<3.

Abstract: A variable magnification optical system that comprises a first lens group having negative refractive power, a first intermediate lens group having positive refractive power, a second intermediate lens group, and a rear lens group having at least one focusing lens group which is moved upon carrying out focusing from an infinitely distant object to a closely distant object. The variable magnification optical system is constructed such that, upon varying a magnification from a wide angle end state to a telephoto end state, the first lens group is moved along the optical axis, a distance between the first lens group and the first intermediate lens group is varied, a distance between the first intermediate lens group and the second intermediate lens group is varied, a distance between the second intermediate lens group and the rear lens group is varied, and predetermined conditional expressions are satisfied.

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 and a succeeding lens group (GR). In the zoom optical system, upon zooming, distances between adjacent lens groups change, and the succeeding lens group (GR) includes a plurality of focusing lens groups that have positive refractive powers and move upon focusing.

Abstract: A variable power optical system includes a plurality of lens groups. During variable magnification, an interval between adjacent lens groups changes. The plurality of lens groups include: a first focusing lens group that moves during focusing; and a second focusing lens group that is disposed more toward an imaging surface side than the first focusing lens group and that moves along a different trajectory than the first focusing lens group during focusing. The first focusing lens group and the second focusing lens group both have a negative refractive power. The first focusing lens group or the second focusing lens group includes at least one lens having a positive refractive power, and is configured so as to satisfy the following condition: 1.40<fFP/(?fFN)<3.50.

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; and a subsequent lens group (GR), wherein upon zooming, a distance between the first lens group (G1) and the second lens group (G2) changes, a distance between the second lens group (G2) and the third lens group (G3) changes, and a distance between the third lens group (G3) and the subsequent lens group (GR) changes, the subsequent lens group (GR) comprises a focusing lens group that moves upon focusing, and the second lens group (G2) comprises a partial group that satisfies following conditional expressions, 1.40<fvr/f2<2.30, 1.80<f1/fw<3.

Abstract: A variable power optical system (ZL (1)) includes a plurality of lens groups (G1-G7). During variable magnification, an interval between adjacent lens groups changes. The plurality of lens groups include: a first focusing lens group (G5) that moves during focusing; and a second focusing lens group (G6) that is disposed more toward an imaging surface side than the first focusing lens group and that moves along a different trajectory than the first focusing lens group during focusing. The first focusing lens group and the second focusing lens group both have a negative refractive power. The plurality of lens groups satisfy the following condition: 0.40<fF1/fF2<3.50 (wherein fF1 is the focal distance of the first focusing lens group, and fF2 is the focal distance of the second focusing lens group).

Abstract: A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M1 lens group (GM1) having a negative refractive power; an M2 lens group (GM2) having a positive refractive power; and an RN lens group (GRN) having a negative refractive power, wherein upon zooming, distances between the front lens group and the M1 lens group, between the M1 lens group and the M2 lens group, and between the M2 lens group and the RN lens group change, upon focusing from an infinite distant object to a short distant object, the RN lens group moves, and the M2 lens group comprises an A lens group that satisfies a following conditional expression, 1.10<fvr/fTM2<2.00, where, fvr: a focal length of the A lens group, and fTM2: a focal length of the M2 lens group in a telephoto end state.