The zoom lens consists of, in order from the object side, a first lens group that has a negative refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; and a fourth lens group that has a positive refractive power. During zooming, in each lens group, distances between the adjacent groups in the direction of the optical axis are changed. The first lens group consists of, in order from the object side, a first lens having a negative refractive power, a second lens having a negative refractive power, and a third lens having a positive refractive power. The third lens group consists of a negative lens. During focusing, only the third lens group moves along the optical axis. The zoom lens satisfies predetermined conditional expressions.

An optical lens assembly includes: a diaphragm, a zoom lens group, a light deflecting assembly and a compensating lens group sequentially arranged along an optical axis and from an object side to an imaging plane. The optical axis comprises a first optical axis segment between the diaphragm and the light deflecting assembly, and a second optical axis segment between the light deflecting assembly and the compensating lens group. The zoom lens group is located on the first optical axis segment, and the first optical axis segment is different from the second optical axis segment. The optical lens assembly may be incorporated in a camera unit and an electronic device.

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.

The zoom lens consists of, in order from the object side, a first lens group that has a negative refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; and a fourth lens group that has a positive refractive power. During zooming, in each lens group, distances between the adjacent groups in the direction of the optical axis are changed. The first lens group consists of, in order from the object side, a first lens having a negative refractive power, a second lens having a negative refractive power, and a third lens having a positive refractive power. The third lens group consists of a negative lens. During focusing, only the third lens group moves along the optical axis. The zoom lens satisfies predetermined conditional expressions.

A zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a rear unit including one or more lens units. Distances between adjacent lens units change during zooming. The first lens unit includes a negative lens made of resin. The rear unit includes a positive lens made of resin. A predetermined condition is satisfied.

A variable magnification optical system comprising, in order from an object side, 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 a magnification, a distance between the first lens group and the second lens group being varied, a distance between the second lens group and the third lens group being varied, and a distance between the third lens group and the fourth lens group being varied; the first lens group consisting of, in order from the object side, a negative lens and a positive lens; and the second lens group consisting of, in order from the object side, a 2a lens group having positive refractive power, a 2b lens group having positive refractive power, and a 2c lens group having negative refractive power, whereby the variable magnification optical system having high optical performance and being downsized, is provided.

A zoom lens (ZL) comprises, in order from an object: a first lens group (G1) having negative refractive power; an aperture stop (S); a second lens group (G2) having positive refractive power; a third lens group (G3) having negative refractive power; and a fourth lens group (G4) having positive refractive power. In this zoom lens (ZL), upon zooming from a wide angle end state to a telephoto end state, a distance between the aperture stop (S) and the first lens group (G1), a distance between the aperture stop (S) and the second lens group (G2), and a distance between the aperture stop (S) and the third lens group (G3) are changed and the aperture stop (S) is moved in an optical axis direction.

A zoom lens system (10) for imaging, includes, in order from an object side (11); a first lens group (G1) with negative refractive power that moves at the time of zooming; a second lens group (G2) with a positive refractive power that moves at the time of zooming, the second lens group including an aperture stop (St); a third lens group (G3) with a positive refractive power, the position of which is fixed relative to the image plane. The second lens group includes: a first sub-lens group (S1) with a positive refractive power arranged on the object side and having the aperture stop; and a second sub-lens group (S2) with a negative refractive power arranged on the image plane side and configured to move independently of the first sub-lens group at the time of focusing.

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.

An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions,

ndLZ+(0.01425×νdLZ)<2.12, and

0.702<θgFLZ+(0.00316×νdL=), where ndL: a refractive index of the lens with reference to d-line, νdLZ: Abbe number of the lens with reference to d-line, and θgFLZ: a partial dispersion ratio of the lens, wherein θgFLZ is defined by the following expression,

θgFLZ=(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.