Abstract: A zoom lens system, in order from an object side to an image side, comprising: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; a fourth lens unit having negative optical power, and a subsequent lens unit, wherein the first lens unit comprises a negative lens element having negative optical power, and a positive lens element having positive optical power, and wherein the conditions: 1.47<nd2<1.57 and 60<?d2<75 (nd2: a refractive index to a d-line of the positive lens element, ?d2: an Abbe number to a d-line of the positive lens element) are satisfied.

Abstract: A zoom lens system according to the present invention, from an object side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth units all move along the optical axis. The third lens unit is composed of three or more lens elements. The condition (6): nd8?1.5 and vd8?75 and the condition (7): (nd9?1)+(nd10?1)?1.55 are satisfied (where, 16<fT/fW, ?>35, and in the third lens unit: nd8, nd9, nd10 are refractive indices to the d-line of the lens elements located on the most object side and at the second and the third positions from the object side; vd8 is an Abbe number to the d-line of the lens element on the most object side; ? is a half view angle at a wide-angle limit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit).

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power, and at least one subsequent lens unit having optical power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units are moved along an optical axis such that an air space between at least any two lens units among the lens units should vary, so that variable magnification is achieved, wherein the first lens unit includes a lens element having a reflecting surface for bending a light beam incident from the object, and wherein the condition is satisfied: 0.20<|fG1|/fT<0.52 (fT/fW?4.0, fG1 is a composite focal length of the first lens unit, and each of fT and fW is a focal length of the entire system at a telephoto limit or a wide-angle limit), an imaging device and a camera are provided.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a positive first lens unit, a negative second lens unit, a positive third lens unit, and a positive fourth lens unit, wherein the first lens unit is composed of a cemented lens element of one object side negative lens element and one image side positive lens element, the fourth lens unit is composed of one lens element, in zooming, the first to fourth lens units are individually moved along an optical axis so that air spaces between the respective lens units vary for magnification change, and the conditions: vdL12<43.50 and fT/fW?6.0 (vdL12: an Abbe number of the positive lens element in the first lens unit, fT and fW: focal lengths of the entire system at a telephoto limit and a wide-angle limit) are satisfied; an imaging device; and a camera.

Abstract: A zoom lens system according to the present invention, from an object side to an image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth lens units all move along the optical axis. The conditions (1): 0<?(f4·fW·tan ?)/LW<0.13 and (2): 0.05?f3/f4?0.97 are satisfied (where, 16<fT/fW, ?>35; ? is a half view angle at a wide-angle limit; LW is an overall optical axial length of the entire system at a wide-angle limit; f3 is a focal length of the third lens unit; f4 is a focal length of the fourth lens unit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit).

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, in order from an object side to an image side, a first lens unit having positive optical power and composed of not more than two lens elements, a second lens unit having negative optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power. In zooming from a wide-angle limit to a telephoto limit, the fourth lens unit moves along an optical axis. Further, the following condition (9) and (10) are satisfied: 1.50<nd1<1.72, 50<vd1<75 (nd1: a refractive index to the d line of a positive lens element constituting the first lens unit, vd1: an Abbe number of a positive lens element constituting the first lens unit).

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, a first lens unit having positive optical power and arranged closest to an object side, a focusing lens unit that moves along an optical axis from an infinity in-focus condition to a close-object in-focus condition, an image blur compensation sub-lens unit that includes at least one lens element and that moves in a direction perpendicular to the optical axis, and an aperture diaphragm arranged on an image side relative to the focusing lens unit and the image blur compensation sub-lens unit. The focusing lens unit, the image blur compensation sub-lens unit, and the aperture diaphragm are adjacent with one another. Further, the following condition (8) is satisfied: 0.7<BFW/fW<3.

Abstract: A compact and lightweight zoom lens system having excellent imaging performance, which is favorably applicable to an interchangeable-lens type digital camera system, is provided. The zoom lens system of the present invention includes, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having negative optical power, a fourth lens unit having positive optical power and including at least one resin lens, and an aperture diaphragm arranged in the fourth lens unit. In zooming from a wide-angle limit to a telephoto limit, an interval between the third lens unit and the fourth lens unit monotonically decreases. Further, the following condition (1) is satisfied: 1.0<T4/fW<3.5 (T4: a thickness of the fourth lens unit in an optical axis direction, fW: a focal length of the entire system at a wide-angle limit).

Abstract: Compact and lightweight zoom lens systems having less aberration fluctuation in association with focusing, lens barrels, interchangeable lens apparatuses, and camera systems are provided. The zoom lens system comprises: a first lens unit having positive optical power; a first focusing lens unit which is located on an image side relative to the first lens unit, has negative optical power, and moves along an optical axis in zooming and focusing; and a second focusing lens unit which is located on the image side relative to the first focusing lens unit, has positive optical power, and moves along the optical axis in the zooming and the focusing, and satisfies the condition: |d2T/d1T|<1.0 (d1T: an amount of movement of the first focusing lens unit in focusing at a telephoto limit, d2T: an amount of movement of the second focusing lens unit in focusing at a telephoto limit).

Abstract: A zoom lens system according to the present invention, from an object side to an image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth lens units all move along the optical axis. The condition (8): 0.15<dG3/dG<0.27 is satisfied (where, 16<fT/fW, ?>35; dG3 is an optical axial center thickness of the third lens unit; dG is a sum of the optical axial thicknesses of the first to the fourth lens units; ? is a half view angle at a wide-angle limit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit). As a result, the zoom lens system has a reduced size and still realizes a wide view angle at a wide-angle limit, as well as a remarkably high zooming ratio and high performance.

Abstract: A zoom lens system according to the present invention, from an object side to an image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth lens units all move along the optical axis. The conditions (1): 0<?(f4·fW·tan ?)/LW<0.13 and (2): 0.05?f3/f4?0.97 are satisfied (where, 16<fT/fW, ?>35; ? is a half view angle at a wide-angle limit; LW is an overall optical axial length of the entire system at a wide-angle limit; f3 is a focal length of the third lens unit; f4 is a focal length of the fourth lens unit; fT T is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit).

Abstract: A zoom lens system according to the present invention, from an object side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth units all move along the optical axis. The third lens unit is composed of three or more lens elements. The condition (6): nd8?1.5 and vd8?75 and the condition (7): (nd9?1)+(nd10?1)?1.55 are satisfied (where, 16<fT/fW, ?>35, and in the third lens unit: nd8, nd9, nd10 are refractive indices to the d-line of the lens elements located on the most object side and at the second and the third positions from the object side; vd8 is an Abbe number to the d-line of the lens element on the most object side; ? is a half view angle at a wide-angle limit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit).

Abstract: A zoom lens system according to the present invention, from an object side to an image side, comprises a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. In zooming, the first to the fourth lens units all move along the optical axis. The condition (8): 0.15<dG3/dG<0.27 is satisfied (where, 16<fT/fW, ?>35; dG3 is an optical axial center thickness of the third lens unit; dG is a sum of the optical axial thicknesses of the first to the fourth lens units; ? is a half view angle at a wide-angle limit; fT is a focal length of the entire system at a telephoto limit; and fW is a focal length of the entire system at a wide-angle limit). As a result, the zoom lens system has a reduced size and still realizes a wide view angle at a wide-angle limit, as well as a remarkably high zooming ratio and high performance.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power, and at least one subsequent lens unit having optical power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units are moved along an optical axis such that an air space between at least any two lens units among the lens units should vary, so that variable magnification is achieved, wherein the first lens unit includes a lens element having a reflecting surface for bending a light beam incident from the object, and wherein the condition is satisfied: 0.20<|fG1|/fT<0.52 (fT/fW?4.0, fG1 is a composite focal length of the first lens unit, and each of fT and fW is a focal length of the entire system at a telephoto limit or a wide-angle limit), an imaging device and a camera are provided.