A variable magnification optical system (ZL) comprises a preceding lens group (GA) having negative refractive power and a succeeding lens group (GB) having positive refractive power, which are arranged in order from the object side along an optical axis. The succeeding lens group (GB) has a focusing group (GF) and an image-side group (GC) disposed closer to the image side than the focusing group (GF), the focusing group (GF) moves to the image side along the optical axis from focusing on an object at infinity to focusing on a close-distance object, and the following conditional expression is satisfied.

1.80<fF/fBaw

FNow<3.40 where fF is the focal length of the focusing group (GF), fBaw is the focal length in the wide-angle end state of an image-side lens group (GBa) composed of lenses disposed on the image side from the focusing group (GF), and FNow is the F-number of the variable magnification optical system (ZL) in the wide-angle end state.

A zoom lens includes a plurality of lens units. The plurality of lens units consist of, in order from an object side to an image side, a first lens unit having a negative refractive power, a middle group including one or more lens units, and a final lens unit having a negative refractive power. Each distance between adjacent lens units changes during zooming. The first lens unit includes at least three negative lenses. Predetermined conditions are satisfied.

The present invention relates to the field of optical lenses and provides a zoom lens consisting of, from an object side to an image side in sequence, a first lens having negative refractive power, a second lens group having positive refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power. During zooming, a distance between adjacent lenses or between lens and adjacent lens group in a direction of an optic axis varies. The second lens group consists of a second lens having positive refractive power, a third lens having negative refractive power, and a fourth lens having negative refractive power, and following conditions are satisfied: f_Tele/f_Wide≥1.80; −1.75≤f3/f2≤−1.35; −1.75≤f4/f2≤−1.35. The present invention becomes compact when contracted, while during imaging, FNO is bright, and has good optical properties.

A zoom optical system consists of a first lens group having negative refractive power, a second lens group having positive refractive power, and a rear lens group which are disposed in order from an object. The rear lens group comprises a last lens group and an F lens group in order from a side closest to an image. Lens groups forming the first lens group, the second lens group, and the rear lens group are configured in such a manner that, upon zooming, the respective lens groups move and a distance between the lens groups adjacent to each other changes. At least a part of the F lens group is configured to move upon focusing. Further, the following conditional expression is satisfied.
−0.220<f1/fE<0.280
where f1: a focal length of the first lens group, and fE: a focal length of the last lens group

A zoom optical system consists of a first lens group having negative refractive power, a second lens group having positive refractive power, and a rear lens group which are disposed in order from an object. The rear lens group comprises a last lens group and an F lens group in order from a side closest to an image. Lens groups forming the first lens group, the second lens group, and the rear lens group are configured in such a manner that, upon zooming, the respective lens groups move and a distance between the lens groups adjacent to each other changes. At least a part of the F lens group is configured to move upon focusing. Further, the following conditional expression is satisfied.

−0.220<f1/fE<0.280

where f1: a focal length of the first lens group, and fE: a focal length of the last lens group

The present disclosure relates to a technical field of optical lenses, and discloses a zoom lens. The zoom lens, being sequentially from an object side to an image side, includes a first lens having a negative refractive power, a second lens group having a positive refractive power, a fifth lens having a positive refractive power, and a sixth lens having a negative refractive power, when zooming, among the first lens, the second lens group, the fifth lens, and the sixth lens, a spacing in an optical axis direction of adjacent lenses or lens groups changes, the second lens group includes a second lens having a positive refractive power, a third lens having a negative refractive power, and a fourth lens having a negative positive power. During photographing, when an F number (FNO) of a wide-angle end is less than or equal to 2.0, the zoom lens becomes bright.

The variable magnification optical system consists of a front group, a middle group, and a rear group, in order from an object side. The front group consists of two or fewer lens groups and has a negative refractive power. The middle group includes only one lens group that has a positive refractive power as a lens group. The rear group consists of three or less lens groups. An aperture stop is disposed between a lens surface closest to an image side in the front group and a lens surface closest to the object side in the rear group. The front group includes at least three negative lenses and at least one positive lens. A negative meniscus lens convex toward the object side is disposed closest to the object side in the front group. The variable magnification optical system satisfies predetermined conditional expressions.

An imaging lens is substantially constituted by: a negative first lens group; a positive second lens group; an aperture stop; a positive third lens group; and a negative fourth lens group; provided in this order from an object side. The first lens group is constituted only by two or more negative lenses. The second lens group has a positive lens at the most object side thereof. The third lens group has a negative lens having a concave surface toward the object side at the most object side thereof. The fourth lens group is constituted by a single negative lens. The fourth lens group moves from the object side to an image side when changing focus from an object at infinity to an object at an extremely close distance. Only the fourth lens group moves during focusing operations.

In an image pickup apparatus including an optical system and an image pickup element, the optical system includes, in order from an object side to an image side, lens(es), an aperture stop, and lens(es). The lens arranged at the most image side in the optical system is a negative lens, and an infrared cut film is formed on at least one lens surface in the optical system. An optical axial distance from the exit pupil of the optical system to the image plane when focusing on an infinite object, an optical axial distance from the lens surface provided with the infrared cut film to the image plane when focusing on the infinite distance object, the curvature radius of the lens surface provided with the infrared cut film, and a radius of a circle circumscribed about an effective imaging area of the image pickup element are appropriately set.

A zoom lens includes, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, the fourth lens group having at least two positive lenses, the zoom lens satisfying a conditional expression (a) of −2.0<f3/f4<−0.35 where f3 indicates a focal length of the third lens group and f4 indicates a focal length of the fourth lens group.