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: 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 includes lens group Gm located on that is closest to an object among lens groups in which a distance between the lens groups changes during zooming, the lens groups having negative power. Lens group Gm includes, in order from the object side toward an image side, lens element LGmF1 having the negative power, lens element LGmF2 having the negative power, both surfaces of lens element LGmF2 having an aspherical shape, and at least two lens elements having power. The present disclosure provides the imaging optical system having good various aberrations such as spherical aberration, astigmatism, and distortion and an imaging device and a camera system that are provided with the imaging optical system.

Abstract: An imaging optical system includes lens group Gm located on that is closest to an object among lens groups in which a distance between the lens groups changes during zooming, the lens groups having negative power. Lens group Gm includes, in order from the object side toward an image side, lens element LGmF1 having the negative power, lens element LGmF2 having the negative power, both surfaces of lens element LGmF2 having an aspherical shape, and at least two lens elements having power. The present disclosure provides the imaging optical system having good various aberrations such as spherical aberration, astigmatism, and distortion and an imaging device and a camera system that are provided with the imaging optical system.

Abstract: An imaging optical system includes a first lens group having positive power, a second lens group, and a third lens group. The first lens group includes a sub-lens group G1A, an aperture stop, and a sub-lens group G1B. The sub-lens group G1A includes a lens L1A1 and a lens L1A2. An object-side surface of the lens L1A1 is convex toward an object. The third lens group includes a lens L3E having negative power and a lens L3P located adjacent to, and closer to the object than, the lens L3E.

Abstract: A zoom lens system includes: a first group of lenses having positive power; a second group of lenses having negative power; a third group of lenses having positive power; a fourth group of lenses having negative power; and a fifth group of lenses having power, which are arranged in this order from an object toward an image. While this system is zooming, intervals between these groups change and the fifth group of lenses moves toward the object. This system satisfies 0.12<T35t/TLt<0.25, where T35t is a distance, measured at telephoto end, from one surface, closest to the image, of the third group of lenses to another surface, closest to the object, of the fifth group of lenses, and TLt is a distance, measured at the telephoto end, from one surface, closest to the object, of the first group of lenses to an image plane.

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 of the present disclosure includes a first lens group having positive power, a second lens group having negative power, a third lens group having the positive power, and a succeeding lens group including one or more lens groups in order from an object side toward an image side. The third lens group includes a lens having the positive power and a lens having the positive power in order from the object side toward the image side, and includes a lens L3R1 having the positive power, a lens L3R2 having the positive power, and a lens L3R3 having the negative power in order from the image side toward the object side. The lens L3R2 and the lens L3R3 are bonded, the lens L3R1 moves to optically correct image blur, and at least a distance between the second lens group and the third lens group changes during zooming from a wide angle end to a telephoto end.

Abstract: A zoom lens system includes: a first group of lenses having positive power; a second group of lenses having negative power; a third group of lenses having positive power; a fourth group of lenses having negative power; and a fifth group of lenses having power, which are arranged in this order from an object toward an image. While this system is zooming, intervals between these groups change and the fifth group of lenses moves toward the object. This system satisfies 0.12<T35t/TLt<0.25, where T35t is a distance, measured at telephoto end, from one surface, closest to the image, of the third group of lenses to another surface, closest to the object, of the fifth group of lenses, and TLt is a distance, measured at the telephoto end, from one surface, closest to the object, of the first group of lenses to an image plane.

Abstract: An imaging optical system includes lens group Gm located on that is closest to an object among lens groups in which a distance between the lens groups changes during zooming, the lens groups having negative power. Lens group Gm includes, in order from the object side toward an image side, lens element LGmF1 having the negative power, lens element LGmF2 having the negative power, both surfaces of lens element LGmF2 having an aspherical shape, and at least two lens elements having power. The present disclosure provides the imaging optical system having good various aberrations such as spherical aberration, astigmatism, and distortion and an imaging device and a camera system that are provided with the imaging optical system.

Abstract: An imaging optical system includes, in order from an object side to an image side, a first lens group having negative optical power, a second lens group having positive optical power, a third lens group having negative optical power, and a fourth lens group with negative optical power. A lens disposed closest to the object side in the second lens group has a concave surface directed toward the object side, and a lens disposed closest to the object side in the fourth lens group has positive optical power. Each distance between the lens groups changes when zooming from a wide-angle end to a telephoto end on photographing.

Abstract: A zoom lens system comprises, in order from an object side to an image side: a first lens group having a positive power; a second lens group having a negative power; an aperture stop, a third lens group having a positive power; and a fourth lens group having a negative power. During zooming, a total length of the zoom lens system does not change, while a distance between each adjacent two of the lens groups changes, and the aperture stop moves along an optical axis independently of the second lens group and the third lens group. The zoom lens system satisfies condition (1) 6.0<f1/fw<20.0 and condition (2) 0.5<|f4|/fw<4.0, where f1 is a focal length of the first lens group, f4 is a focal length of the fourth lens group, and fw is a focal length of the zoom lens system at a wide-angle limit.

Abstract: An imaging optical system includes, in order from an object side to an image side, a first lens group having negative optical power, a second lens group having positive optical power, a third lens group having negative optical power, and a fourth lens group with negative optical power. A lens disposed closest to the object side in the second lens group has a concave surface directed toward the object side, and a lens disposed closest to the object side in the fourth lens group has positive optical power. Each distance between the lens groups changes when zooming from a wide-angle end to a telephoto end on photographing.

Abstract: An imaging optical system of the present disclosure includes a first lens group having positive power, a second lens group having negative power, a third lens group having the positive power, and a succeeding lens group including one or more lens groups in order from an object side toward an image side. The third lens group includes a lens having the positive power and a lens having the positive power in order from the object side toward the image side, and includes a lens L3R1 having the positive power, a lens L3R2 having the positive power, and a lens L3R3 having the negative power in order from the image side toward the object side. The lens L3R2 and the lens L3R3 are bonded, the lens L3R1 moves to optically correct image blur, and at least a distance between the second lens group and the third lens group changes during zooming from a wide angle end to a telephoto end.

Abstract: A zoom lens system comprises, in order from an object side to an image side: a first lens group having a positive power; a second lens group having a negative power; an aperture stop, a third lens group having a positive power; and a fourth lens group having a negative power. During zooming, a total length of the zoom lens system does not change, while a distance between each adjacent two of the lens groups changes, and the aperture stop moves along an optical axis independently of the second lens group and the third lens group. The zoom lens system satisfies condition (1) 6.0<f1/fw<20.0 and condition (2) 0.5<|f4|/fw<4.0, where f1 is a focal length of the first lens group, f4 is a focal length of the fourth lens group, and fw is a focal length of the zoom lens 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 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; a fifth lens unit; and a sixth lens unit, wherein in zooming from a wide-angle limit to a telephoto limit at a time of image taking, the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit move along an optical axis so that an interval between the third lens unit and the fourth lens unit at the telephoto limit is larger than that at the wide-angle limit, and wherein focusing from an infinity in-focus condition to a close-object in-focus condition is performed by moving the fourth lens unit along the optical axis.

Abstract: A zoom lens system comprising a plurality of lens units each being composed of at least one lens element, and comprising, 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 positive optical power, a fourth lens unit having positive optical power, and a fifth lens unit having negative optical power, wherein the first lens unit is composed of two or less lens elements, the third lens unit is composed of five or more lens elements, and the condition: 5.0<f1/f3<8.0 (f1: a focal length of the first lens unit, f3: a focal length of the third lens unit) is satisfied.

Abstract: An imaging optical system, in order from an object side to an image side, includes: a first lens unit having positive optical power; and a second lens unit. In focusing from an infinity in-focus condition to a close-object in-focus condition, the first lens unit moves along an optical axis, and the second lens unit is fixed with respect to an image surface. The imaging optical system is compact, sufficiently suppresses occurrence of various aberrations, has high resolution from the infinity in-focus condition to the close-object in-focus condition, is bright and highly efficient, and is suitable for wide-angle photographing.

Abstract: A zoom lens system comprising: a positive first lens unit; a negative second lens unit; a positive third lens unit; a fourth lens unit; and at least one subsequent lens unit, wherein the subsequent lens unit(s) includes a negative lens unit, the first and third lens units are respectively composed of two or less lens elements and four or more lens elements, the first and second lens units move along an optical axis in zooming, and the conditions: 0.0<LGmax/LG2<1.5, 0.2<|f2/fW|, and 0.1<|fe/f2| (LGmax: a maximum value of an axial thickness of the subsequent lens unit(s), LG2: an axial thickness of the second lens unit, fW, f2, and fe: focal lengths of the entire system at a wide-angle limit, the second lens unit, and a negative lens unit located closest to the image side) are satisfied.

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; and at least one subsequent lens unit, wherein the subsequent lens unit(s) includes a lens unit having negative optical power, the first lens unit is composed of two or less lens elements, the third lens unit is composed of four or more lens elements, the first lens unit and the second lens unit move along an optical axis in zooming, and the condition: 0<|fW/fe<2 (fe: a focal length of a lens unit having negative optical power and located closest to the image side in the entire system, fW: a focal length of the entire system at a wide-angle limit) is satisfied.