In an optical system, a height from an optical axis of a paraxial marginal ray that passes through a lens surface closest to an object is smaller than a maximum height from the optical axis of the paraxial marginal ray that passes through a lens surface on an image side of an intersection between the optical axis and a paraxial chief ray. The optical system includes an optical element disposed on an object side or the image side of the intersection. The optical element has positive refractive power in a case where the optical element is disposed on the object side of the intersection, and has negative refractive power in a case where the optical element is disposed placed on the image side of the intersection. A predetermined condition is satisfied.

A zoom lens includes a first lens group having negative refractive power; a second lens group having positive refractive power; a third lens group having negative refractive power and a fourth lens group having positive refractive power. Upon varying magnification, distances between the first lens group and the second lens group, between the second lens group and the third lens group and between the third lens group and the fourth lens group vary. The second lens group includes a front lens group, an aperture stop, and a rear lens group. Each of the front lens group and the rear lens group includes at least one positive lens. At least a part of the lenses in the second lens group is moved as a group to have a component in a direction perpendicular to an optical axis.

A variable magnification optical system includes, in order from an object: a first lens group (G1) having a negative refractive power; a second lens group (G2) having a positive refractive power; a third lens group (G3) having a negative refractive power; and a fourth lens group (G4) having a positive refractive power. The system performs varying magnification by changing the distance between the first lens group and the second lens group, the distance between the second lens group and the third lens group, and the distance between the third lens group and the fourth lens group. The third lens group includes a 32nd lens group (G32) configured to be movable so as to have a component in a direction orthogonal to an optical axis in order to correct image blur as a vibration-reduction lens group (VR) and a 31st lens group (G31) disposed at an object-side of the 32nd lens group. The 32nd lens group has negative refractive power, and the system satisfies Conditional Expression (1) below.

0.200<f1/f3<0.900(1)

A variable magnification optical system includes: a first lens group (G1) having a negative refractive power; a second lens group (G2) having a positive refractive power; an intermediate group (Gn) disposed closer to an image side than the second lens group (G2); and a vibration-reduction lens group (VR) disposed closer to the image side than the intermediate group (Gn) and configured to be movable so as to have a component in a direction orthogonal to an optical axis. The system performs varying magnification by changing at least the distance between the first lens group (G1) and the second lens group (G2) and the distance between the second lens group (G2) and the intermediate group (Gn), and the system satisfies Conditional Expression (1).

1.000<f(1Gn)t/ft<100.000(1)

A zoom lens comprises four lens unit, and at the time of zooming, each of a distance between a first positive lens unit and a first negative lens unit and a distance between a second negative lens unit and a second positive lens unit changes, and a distance between the first positive lens unit and the second negative lens unit widens more at the telephoto end than at the wide angle end, and the first positive lens unit includes an object-side sub-lens unit and an image-side sub-lens unit, and an aperture stop is disposed between the object-side sub-lens unit and the image-side sub-lens unit, and the first negative lens unit includes a negative lens and a positive lens, and a refracting surface nearest to an image in the first negative lens unit is concave toward the image side, and a refracting surface nearest to an object in the second positive lens unit is concave toward the object side, and a refracting surface nearest to the image in the second positive lens unit is convex toward the image side, and the zoom lens satisfies predetermined conditional expressions.

A zoom lens according to the present invention includes sequentially from an object side: a first lens group having negative refractive power, and a second lens group having positive refractive power, and performs a magnification change operation by changing a gap between the adjacent lens groups. The zoom lens has specific optical characteristics represented by four expressions relating to the second lens group.

A zoom lens consists of, in order from an object, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens group having a positive refractive power. Zooming is performed by changing respective distances between the first and second lens groups, the second and third lens groups, and the third and fourth lens groups. The first lens group consists of, in order from an object, a negative lens, a negative lens and a positive lens, the second lens group consists of five lenses, and the third lens group consists of a bi-concave negative lens.

A variable magnification optical system includes: a first lens group (G1) having a negative refractive power; a second lens group (G2) having a positive refractive power; an intermediate group (Gn) disposed closer to an image side than the second lens group (G2); and a vibration-reduction lens group (VR) disposed closer to the image side than the intermediate group (Gn) and configured to be movable so as to have a component in a direction orthogonal to an optical axis. The system performs varying magnification by changing at least the distance between the first lens group (G1) and the second lens group (G2) and the distance between the second lens group (G2) and the intermediate group (Gn), and the system satisfies Conditional Expression (1).

1.500<(Gn)t<100.000(1) where (Gn)t: an imaging magnification of the intermediate group (Gn) in a telephoto end state

A composite optical element includes a glass lens and a resin lens that are joined together. The resin lens has an aspheric shape. When Nd is a refractive index of the resin lens, ?d is an Abbe number of the resin lens, and ?gF is a partial dispersion ratio of the resin lens, Nd, ?d, and ?gF are appropriately set.

A zoom lens includes, in order from an object, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens group. Zooming is performed by changing respective distances between the first and second lens groups, the second and third lens groups, and the third and fourth lens groups. The first lens group includes a negative lens disposed closest to the object, and a negative lens. Specified conditional expressions are satisfied.