A zoom lens includes, in order from a magnified side to a minified side, a first lens group, an aperture stop, and a second lens group. The second lens group has at least one aspheric surface. The zoom lens satisfies the conditions: 0.1<Ic/TTLw<0.15 and TTLw/EFLw≦10, where Ic denotes a radius of an image circle, TTLw denotes a total track length of the zoom lens in the wide configuration, and EFLw denotes an effective focal length of the zoom lens in the wide configuration.

A zoom lens includes, in order from a magnified side to a minified side, a first lens group, an aperture stop, and a second lens group. The second lens group has at least one aspheric surface. The zoom lens satisfies the conditions: 0.1<Ic/TTLw<0.15 and TTLw/EFLw≦10, where Ic denotes a radius of an image circle, TTLw denotes a total track length of the zoom lens in the wide configuration, and EFLw denotes an effective focal length of the zoom lens in the wide configuration.

A zoom lens includes, in order from an object along an optical axis: 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; a fourth lens group; and a fifth lens group. When the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis.

A zoom lens includes, in order from an object along an optical axis: 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; a fourth lens group; and a fifth lens group. When the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis.

An imaging optical system includes a first lens unit (B1) having a negative refractive power configured not to move for zooming from a wide-angle end to a telephoto end, and a plurality of lens units (B2 to B7) configured to move so that a space between lens units adjacent to each other changes during the zooming, the first lens unit includes a first lens subunit (B1a) having a negative refractive power, a second lens subunit (B1b) having a negative refractive power, and a third lens subunit (B1c) having a positive refractive power, the first lens subunit (B1a) is configured not to move for focusing from an infinity to a close range, and the second lens subunit (B1b) and the third lens subunit (B1c) constitute a focus moving unit configured to move, during the focusing, while a space between the second and third lens subunits is narrowed.

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.

A zoom lens comprising in order from an object side, a first lens unit having a negative refractive power, a second lens unit having a negative refractive power, a lens unit having a positive refractive power, and a rearmost lens unit having a negative refractive power, and the rearmost lens unit is positioned nearest to an image in the plurality of lens units, and at the time of zooming, distances between the lens units in the plurality of lens units change. Moreover, an image pickup apparatus includes the zoom lens, and an image pickup element having an image pickup surface.

A zoom lens comprising in order from an object side, a first lens unit having a negative refractive power, a second lens unit having a negative refractive power, a lens unit having a positive refractive power, and a rearmost lens unit having a negative refractive power, and the rearmost lens unit is positioned nearest to an image in the plurality of lens units, and at the time of zooming, distances between the lens units in the plurality of lens units change. Moreover, an image pickup apparatus includes the zoom lens, and an image pickup element having an image pickup surface.

A zoom optical system includes a plurality of lens units, the plurality of lens units consist of lens units having a positive refractive power and lens units having a negative refractive power, and the lens units having a positive refractive power include a positive lens unit and an image-side positive lens unit, the image-side positive lens unit is not moved, in the lens plurality of units, a space between the lens units disposed adjacently is changed at a time of zooming, at a time of focusing, or at a time of zooming and at a time of focusing, the positive lens unit includes a predetermined positive lens satisfying the following Conditional Expression (2), and the following Conditional Expression (1) is satisfied:

0.1≦fGBUN1/fGPM≦2.1  (1), and

60.8≦νdGPMP1≦100.0  (2).

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.