Abstract: A zoom lens system includes: a first lens group having positive power; a second lens group having negative power; a third lens group having positive power; a fourth lens group having positive power; a fifth lens group having negative power; and a following lens group following the fifth lens group. The first to fifth lens groups and the following lens group are arranged in this order such that the first lens group is located closest to an object and that the following lens group is located closest to an image. While the zoom lens system is zooming, intervals between the respective lens groups change. While the zoom lens system is focusing from an infinity focus point through a shortest shooting range, a plurality of negative lens groups included in the fifth lens group and the following lens group move.

Abstract: An imaging optical system consists of a first lens group having positive power, a second lens group having power; and a third lens group having power. The first lens group and the third lens group are immobile along an optical axis and the second lens group moves along the optical axis while the imaging optical system is focusing. The first lens group consists of: a sub-lens group G1A; an aperture stop; and a sub-lens group G1B. The sub-lens group G1A includes: a meniscus lens L1A1 having positive power and having a convex surface facing the object; a meniscus lens L1A2 having negative power and having a convex surface facing the object; and a meniscus lens L1A3 having negative power and having a convex surface facing the object.

Abstract: A zoom lens system includes: a first lens group having positive power; a second lens group having negative power; a third lens group having positive power; a fourth lens group having positive power; a fifth lens group having negative power; and a following lens group following the fifth lens group. The first to fifth lens groups and the following lens group are arranged in this order such that the first lens group is located closest to an object and that the following lens group is located closest to an image. While the zoom lens system is zooming, intervals between the respective lens groups change. While the zoom lens system is focusing from an infinity focus point through a shortest shooting range, a plurality of negative lens groups included in the fifth lens group and the following lens group move.

Abstract: A zoom lens system includes, in order from an object side to an image side: a first lens group having positive power; a second lens group having negative power; a third lens group having positive power; a fourth lens group having negative power; a fifth lens group having positive power; and a sixth lens group having power. During zooming from wide angle extremity to telephoto extremity, the distance between respective lens groups changes. The fifth lens group is composed of at most two lens elements, at least one of which is a concave meniscus lens element having a convex surface facing the object side.

Abstract: A zoom lens system includes: a first lens group having positive power; a second lens group having negative power; a third lens group having positive power; a fourth lens group having positive power; a fifth lens group having negative power; and a following lens group following the fifth lens group. The first to fifth lens groups and the following lens group are arranged in this order such that the first lens group is located closest to an object and that the following lens group is located closest to an image. While the zoom lens system is zooming, intervals between the respective lens groups change. While the zoom lens system is focusing from an infinity focus point through a shortest shooting range, a plurality of negative lens groups included in the fifth lens group and the following lens group move.

Abstract: A zoom lens system includes, in order from an object side to an image side: a first lens group having positive power; a second lens group having negative power; a third lens group having positive power; a fourth lens group having negative power; a fifth lens group having positive power; and a sixth lens group having power. During zooming from wide angle extremity to telephoto extremity, the distance between respective lens groups changes. The fifth lens group is composed of at most two lens elements, at least one of which is a concave meniscus lens element having a convex surface facing the object side.

Abstract: A zoom lens system is an optical system that includes, in order from an object side to an image side, a first lens group having one first lens element with positive optical power, a second lens group having one second lens element with negative optical power, a third lens group with negative optical power, and a subsequent lens group including at least two lens groups. When zooming, distances between the lens groups change, and condition: 1.65<|f2|/fw<2.20 (where f2: Focal length of the second lens group, and fw: Focal length of the entire system at a wide-angle end) is satisfied.

Abstract: A zoom lens system is an optical system that includes, in order from an object side to an image side, a first lens group having one first lens element with positive optical power, a second lens group having one second lens element with negative optical power, a third lens group with negative optical power, and a subsequent lens group including at least two lens groups. When zooming, distances between the lens groups change, and condition: 1.65<|f2|/fw<2.20 (where f2: Focal length of the second lens group, and fw: Focal length of the entire system at a wide-angle end) is satisfied.