A variable magnification optical system according to the present invention includes, in order from an object side: a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a following lens group, wherein at least the second lens group is moved so that a gap between the first lens group and the second lens group increases and a gap between the second lens group and the third lens group decreases when zooming from a wide angle end to a telephoto end, and a predetermined conditional expression is satisfied.

A zoom lens system includes a positive first lens group, a negative second lens group, a positive intermediate lens group, and a negative image-side lens group. Upon zooming from the short to long focal length extremities, a distance between the first and second lens groups increases, and a distance between the second and intermediate lens groups decreases. The image-side lens group consists of two lens elements. The following conditions are satisfied:

−6.0<f1/f2<−4.3,

−5.4<f1/fIMG<−3.9,

and

0.3<D2/fw<3.0.

f1, f2 and fIMG designate the focal lengths of the first, second and the image-side lens groups, respectively. D2 designates a distance between the second lens group and the intermediate lens group, at the short focal length extremity. fw designates the focal length of the zoom lens system at the short focal length extremity.

The 1-2nd lens group is divided into three lens groups which move when focusing is performed during the magnification change. Even in a case in which the second optical group is formed of one mirror, it is possible for a primary image to contain appropriate aberration and to hereby reduce aberration of an image which is finally projected onto a screen through the second optical group.

An optical system includes, in order from an object side toward an image side, a first lens unit having positive refractive power, and a second lens unit having negative refractive power. A distance between consecutive ones of the lens units changes when focusing is performed. The first lens unit is stationary during focusing. The second lens unit is moved toward the image side when focus is changed from an object at infinity to an object at a short distance. Lateral magnification β2 of the second lens unit when focusing on the object at infinity, focal length f1 of the first lens unit, and focal length f2 of the second lens unit are set appropriately to satisfy predetermined mathematical conditions.

A zoom lens system includes a positive first lens group, a negative second lens group, in that order from the object side, and a positive n.sup.th lens group provided closest to the image side. During zooming from the short to long focal length extremities, the first lens group and the n.sup.th lens group remain stationary and the second lens group moves. A positive m.sup.th lens group is provided between the second and n.sup.th lens groups. The following conditions (1) and (2) are satisfied:
1.23<f1/fn<1.50  (1), and
1.20<fn/fm<1.60  (2),
wherein f1, fn and fm designate the focal lengths of the first, n.sup.th and m.sup.th lens groups, respectively, wherein n is a positive integer of 4 or greater, and m is a positive integer of 3 or greater.

Comprising a first lens group G1 having positive refractive power, disposed at the most object side, and an image side lens group disposed at a side closer to an image than the first lens group G1, upon zooming, at least a distance between the first lens group G1 and the image side lens group being varied, the image side lens group comprising a vibration reduction lens group GVR which is moved so as to have a component in a direction perpendicular to the optical axis and a focusing lens group GF which is moved along the optical axis upon focusing, thereby providing a variable magnification optical system which has a higher optical performance, an optical apparatus and a method for manufacturing a variable magnification optical system.

A lens unit L100 is removably mounted on an image pickup apparatus generating control information used for a vibration control that vibrates a correction lens L105 and moves a vibration center of the correction lens L105, includes an image pickup optical system including a magnification varying lens L102 and the correction lens L105, a storage unit storing first information indicating a relation between positions of the magnification varying lens L102 and the correction lens L105, and a lens controller performing a predetermined control in which the correction lens L105 moves in accordance with the movement of the magnification varying lens L102, and the lens controller sends information relating to the magnification varying operation to the image pickup apparatus, and overlaps the vibration control of the correction lens L105 based on the control information in accordance with the information relating to the magnification varying operation with the predetermined control.

A mobile terminal includes a terminal body, and a camera module provided on one side of the terminal body and including a lens assembly exposed outwardly in at least a portion thereof, an iris provided on an inner side of the lens assembly to adjust an amount of incident light, and an actuator moving the lens assembly and the iris, wherein the lens assembly includes a first lens assembly provided on a front side of the iris and exposed to the outside and a second lens assembly provided on a rear side of the iris and determining a magnification together with the first lens assembly, the actuator includes a moving member disposed on a rear side of the second lens assembly, a housing accommodating the moving member, and a driving unit provided between the moving member and the housing.

An optical lens includes a first lens group, a second lens group and an aperture stop disposed between the first lens group and the second lens group. The optical lens satisfies the conditions of 7 mm<D<25 mm and 0.3<D/LT<0.5, where D is a diameter of a lens surface of the second lens group furthest from the first lens group and LT is a total lens length measured along an optical axis between a lens surface of the first lens group furthest from the second lens group and the lens surface of the second lens group furthest from the first lens group.

An optical lens includes a first lens group, a second lens group and an aperture stop disposed between the first lens group and the second lens group. The optical lens satisfies the conditions of 7 mm<D<25 mm and 0.3<D/LT<0.5, where D is a diameter of a lens surface of the second lens group furthest from the first lens group and LT is a total lens length measured along an optical axis between a lens surface of the first lens group furthest from the second lens group and the lens surface of the second lens group furthest from the first lens group.