A zoom lens includes, in order from the object side, a positive first lens unit not moving for zooming, a negative second lens unit moving for zooming, positive third and fourth lens units moving for zooming, and a positive fifth lens unit not moving for zooming. Intervals between adjacent ones of the first to fifth lens units change for zooming. The third lens unit consists of positive, positive, and negative lenses in order from the object side. Appropriate settings are made to the zoom lens's focal lengths at the wide angle and telephoto ends, the lateral magnifications of the second lens unit at the wide angle and telephoto ends, the focal lengths of the third lens unit and the negative lens in the third lens unit, and the average Abbe number of the positive lenses and the Abbe number of the negative lens in the third lens unit.

A zoom lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; an intermediate lens group that consists of one or two lens groups; and a final lens group, wherein during zooming, the second lens group moves along an optical axis, and all distances between adjacent lens groups change.

A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power are arranged in order from an object, and zooming is performed by changing distances between each lens group, and the first lens group (G1) is composed of three or more lenses, the fourth lens group (G4) is composed of two or less lenses, and the fifth lens group (G5) is composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and the following conditional expression (1) is satisfied.

8.40<f1/(?f2)(1) where, f1 denotes a focal length of the first lens group (G1), and f2 denotes a focal length of the second lens group (G2).

On embodiment of the invention discloses an optical lens including five lens group and an aperture stop. Each lens group includes at least one lens with refractive power, and the aperture stop is fixed in a position between a second lens group and a third lens group. Further, a distance between a first lens group and a fifth lens group remains fixed during zooming or focusing, and respective distances of the second lens group and a fourth lens group relative to the fifth lens group vary during zooming or focusing.

A first lens group (G1) having positive refractive power, a front-side lens group (GX), an intermediate lens group (GM) having positive refractive power, and a rear-side lens group (GR) are arranged in order from an object side. The front-side lens group (GX) is composed of one or more lens groups and has a negative lens group At least part of the intermediate lens group (GM) is a focusing lens group(GF). The rear-side lens group (GR) is composed of one or more lens groups. Upon zooming, the first lens group (G1) is moved with respect to an image surface, a distance between the first lens group (G1) and the front-side lens group (GX) is changed, a distance between the front-side lens group (GX) and the intermediate lens group (GM) is changed, and a distance between the intermediate lens group (GM) and the rear-side lens group (GR) is changed.

A zoom lens includes, from an object side a first lens unit (a positive refractive power) configured not to move for zooming, two or more intermediate lens units configured to move in zooming, and a rear lens unit (a positive refractive power), wherein an interval between each pair of adjacent lens units changes in zooming, the first lens unit includes, from the object side, a first lens subunit (a negative refractive power) configured not to move for focusing, a second lens subunit (a positive refractive power) configured to move for focusing, and a third lens subunit (a positive refractive power), the zoom lens satisfies specific inequalities concerning a focal length of the first lens unit, a length on an optical axis from a last surface to a rear principal point of the first lens unit, and a focal length of the zoom lens at a telephoto end.

A zoom optical system comprises, in order from an object side: a first lens group having positive refractive power; a front-side lens group; an intermediate lens group having positive refractive power; and a rear-side lens group. The front-side lens group is composed of one or more lens groups and has a negative lens group. At least part of the intermediate lens group is a focusing lens group. The rear-side lens group is composed of one or more lens groups. Upon zooming, the first lens group is moved with respect to an image surface and distances between the first lens group and the front-side lens group, between the front-side lens group and the intermediate lens group, and between the intermediate lens group and the rear-side lens group change. The following conditional expressions are satisfied:
?0.750<fF/fRF<4.000
2.250<TLW/ZD1<5.000
32.000?W?
where fF denotes a focal length of the focusing lens group, fRF denotes a focal length of a lens group closest to the object side in the rear-side lens group, TLW denotes an entire length of the optical system in a wide angle end state, ZD1 denotes a movement amount of the first lens group upon zooming from the wide angle end state to a telephoto end state, and W? denotes a half angle of view in the wide angle end state.

A variable magnification optical system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and at least one lens unit. A second predetermined positive lens element satisfies conditional expressions (1) and (2) and a second predetermined negative lens element satisfies the following conditional expressions (3) and (4). The second lens unit includes three sub-lens units and the following conditional expressions (5) and (6) are satisfied:
0.520<(g,F)G2p<0.610(1),
0.680<(C,t)G2p<0.900(2),
0.520<(g,F)G2n<0.560(3),
0.750<(C,t)G2n<0.900(4),
0.25<fG21/fG22<0.90(5), and
0.70<fG21/fG23<0.40(6).

Provided is the image pickup apparatus including an optical system forming an image of an object, an image pickup element receiving light from optical system, a driving unit driving at least one of an optical element included in optical system and image pickup element in a direction including a component of a direction perpendicular to an optical axis of optical system, and a determining unit performing first determination that driving unit is set to be in a non-driving state (NDS) or performing second determination that driving unit is set to be in a driving state (DS) based on information regarding object. When first determination is performed, determining unit outputs a signal for maintaining driving unit in NDS or switching driving unit from DS to NDS. When second determination is performed, determining unit outputs a signal for maintaining driving unit in DS or switching driving unit from NDS to DS.

A zoom lens consists of, in order from an object side, a positive first lens group fixed relative to the image surface during zooming, at least two movable lens groups including a negative second lens group being adjacent to the first lens group, the at least two movable lens groups being movable by changing a distance in an optical-axis direction to an adjacent group during zooming; and a final lens group arranged on the most image side and fixed relative to the image surface during zooming. The first lens group has, continuously in order from the most object side, a first negative lens having a concave surface facing an image side, a second negative lens, and a third positive lens. A predetermined conditional expression relating to the first lens group is satisfied.