Provided is a zoom lens comprising in order from an object side to an image side, a positive first lens unit including a diffractive optical element, a negative second lens unit, a positive third lens unit including at least one positive lens, and a rear unit including one or more lens units, in which intervals between adjacent lens units are changed during zooming. The third lens unit comprises a positive lens formed by using a material with an Abbe number and a partial dispersion ratio concerning a C-line and a t-line both of which are appropriately set. In the zoom lens, a focal length of the first lens unit and a back focus of the zoom lens when focusing on infinity at a telephoto end are appropriately set.

A telephoto imaging system includes: a solid lens assembly and a tunable lens assembly. The solid lens assembly includes a first group, a second group, and a third group of solid lenses along the optical axis from the object plane to the image plane. The tunable lens assembly is configured for zooming under the effect of a driving mechanism to achieve focusing on objects at different distances. The following condition is satisfied by the tunable lens assembly when at least an in-focus state exists in the focusing process: 0<|delta(f/ft)|<0.9.

A zoom lens includes, in order from an object side to an image side, 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 a rear lens group including one or more lens units. For zooming, the first to third lens units move, thereby changing intervals between adjacent ones of these lens units. For the zoom lens, a focal length (f1) of the first lens unit, focal lengths (fw, ft) of the zoom lens at a wide angle end and at a telephoto end, respectively, and amounts (M2, M3) by which the second and third lens units, respectively, move when zooming from the wide angle end to the telephoto end are appropriately defined.

A zoom lens including in order from an object side: a positive first unit configured not to move for zooming; a negative second unit configured to move to the image side for zooming to a telephoto end; and a relay lens unit configured not to move for zooming, wherein the first unit consists of five lenses including, in order from the object side, a negative lens, a positive lens, a positive lens, a positive lens and a positive lens, or six lenses including, in order from the object side, a positive lens, a negative lens, a positive lens, a positive lens, a positive lens and a positive lens, and a refractive index of the negative lens in the first unit, an Abbe number of the negative lens, a focal length of the negative lens, and a focal length of the first lens unit are appropriately set.

Provided is a zoom lens, including, in order from an object side to an image side: a positive first lens unit; a negative second lens unit; a positive third lens unit; and a rear lens group including at least one lens unit, in which the first lens unit is not configured to move for zooming, and the second lens unit, the third lens unit, and at least one lens unit included in the rear lens group are configured to move during zooming so that intervals between adjacent lens units are changed during zooming. A lateral magnification of the second lens unit at a wide angle end, a lateral magnification of the second lens unit at a telephoto end, a movement amount of the third lens unit during zooming from the wide angle end to the telephoto end, and a total length of the zoom lens are appropriately set.

To obtain a zoom lens easily performing image blur correction and maintaining optical performance while performing image blur correction while restricting an increase in size of the lens. A zoom lens including, in order from an object side: a positive first unit; a negative second unit; a positive third unit; and a rear group that has one or more units. Spacings between adjacent units change during zooming. First and second correction systems rotatable about first and second centers on or in the vicinity of an optical axis during blur correction are respectively constituted by at least a part of the second unit and at least a part of an optical system disposed on image side of the second unit. The first and second centers are on image side of a surface vertex of the respective first and second correction systems closest to the object side.

Provided is a zoom lens, including, in order from object side: a positive first unit; a negative second unit; a third unit having a positive or positive refractive power; and a rear group including at least one unit, in which: the first unit is not moved for zooming, and intervals between adjacent units are changed during zooming; the first unit includes three lenses, and the second unit includes three lenses; at least two lens surfaces, among lens surfaces of lenses included in the second unit except for a lens arranged closest to the object side, have aspherical shapes; and focal lengths of the zoom lens at a wide angle end and at a telephoto end, movement amounts of the second and third units during zooming from the wide angle end to the telephoto end are appropriately set.

An optical imaging lens includes a first lens element, a second lens, an aperture stop, a third lens element and a fourth lens element from an object side to an image side in order along an optical axis, and each lens element has an object-side surface and an image-side surface. An optical axis of the image-side surface of the first lens element is convex and an optical axis of the image-side surface of the fourth lens element is concave. HFOV stands for the half field of view of the entire optical imaging lens and TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis to satisfy HFOV/TTL1.500/mm.

A zoom lens system includes a first lens group; a second lens group; and a subsequent lens group arranged in that order from the object side. The second lens group consists of a second lens group-a, a second lens group-b, and a second lens group-c arranged in that order from the object side. A distance between the first lens group and the second lens group increases and a distance between the second lens group and the subsequent lens group decreases during a change in magnification from a short focal length end to a long focal length end. During a change in focus from infinity to a short distance, the second lens group-b is movable to the image side, and a distance between the second lens group-a and the second lens group-b and a distance between the second lens group-b and the second lens group-c are changeable.

A zoom lens including, in order from object side, a positive first lens unit not moving for zooming, a negative second lens unit moving during zooming, at least one other lens unit moving during zooming as at least a third lens unit, and a rearmost lens unit closest to an image side not moving for zooming, and also including an aperture stop at the image side of the second lens unit, average values of Abbe numbers and relative partial dispersions of each of positive lenses and negative lenses forming the second lens unit, anomalous dispersion of a lens having a smallest Abbe number of negative lenses forming the rearmost lens unit, an axial distance between surface vertex positions of lenses closest to the object and image sides of the zoom lens, and a distance between the aperture stop and the negative lens at a wide angle end are appropriately set.