Abstract: A system consists of a front lens unit and a negative lens on an image side of the front lens unit. A focal length of the system, a focal length of the negative lens, an effective diameter of a lens surface on an object side of the negative lens, a diameter of an aperture stop that determines an on-axis ray, and an on-axis distance from an endmost point in a light effective area of the lens surface on the object side of the negative lens to an on-axis point of the negative lens satisfy predetermined inequalities.

Abstract: An optical system 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 positive refractive power, and a third lens unit having a positive refractive power. During focusing from infinity to a short distance, the first lens unit is fixed, and the second lens unit and the third lens unit are moved so that a distance between the second lens unit and the third lens unit changes. Predetermined conditions are satisfied.

Abstract: 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.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having negative refractive power, and a rear group that includes one or more lenses and has positive refractive power. In the zoom lens, a distance between lens units arranged next to each other changes during zooming. At least one of the lens units provided on the image side of the third lens unit includes a resin lens having positive refractive power and a resin lens having negative refractive power. A material of the resin lens having positive refractive power and a material of the resin lens having negative refractive power are set appropriately.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a rear lens group including a lens unit having negative refractive power arranged along an optical axis thereof. A focal length fw of the zoom lens at a wide-angle end, a focal length ft of the zoom lens at a telephoto end, an amount of movement M1 of the first lens unit on the optical axis in zooming from the wide-angle end to the telephoto end, and a focal length frn of a lens unit Lrn that is a lens unit having a shortest focal length among lens units having negative refractive power included in the rear lens group are appropriately set based on predetermined mathematical conditions.

Abstract: 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.

Abstract: A zoom lens including: 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, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power in this order from an object side to an image side. During zooming, the lens units move such that an interval between adjacent lens units varies. The third lens unit includes at least two positive lenses. A partial dispersion ratio (?gF3P) of a material and the Abbe number (?d3P) of a positive lens included in the third lens unit satisfy the following conditional expressions, ?gF3P?(?1.665×10?7·?d3P3+5.213×10?5·?d3P2?5.656×10?3·?d3P+0.737)>0 50.0<?d3P<100.0.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having negative refractive power, and a rear group that includes one or more lenses and has positive refractive power. In the zoom lens, a distance between lens units arranged next to each other changes during zooming. At least one of the lens units provided on the image side of the third lens unit includes a resin lens having positive refractive power and a resin lens having negative refractive power. A material of the resin lens having positive refractive power and a material of the resin lens having negative refractive power are set appropriately.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having negative refractive power, and a fifth lens unit having positive refractive power. At least the first, second, and third lens units move during zooming so that the first lens unit is located closer to an object side than an image side, the second lens unit is located closer to the image side, and the third lens unit is located closer to the object side at a telephoto end than a wide-angle end. Movement, focal length, and positioning parameters of first to third lens units, during zooming from the wide-angle end toward the telephoto end, are appropriately set based on mathematical conditions.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a rear lens group including a lens unit having negative refractive power arranged along an optical axis thereof. A focal length fw of the zoom lens at a wide-angle end, a focal length ft of the zoom lens at a telephoto end, an amount of movement M1 of the first lens unit on the optical axis in zooming from the wide-angle end to the telephoto end, and a focal length frn of a lens unit Lrn that is a lens unit having a shortest focal length among lens units having negative refractive power included in the rear lens group are appropriately set based on predetermined mathematical conditions.

Abstract: A zoom lens includes a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a third lens unit of a positive refractive power, and a rear lens group including one or more lens units in order from an object side to an image side, the first, second, and third lens units being moved towards an object side during zooming from a wide-angle end to a telephoto end with respect to an image plane, wherein the first lens unit includes a positive lens and a negative lens, and movement amounts of the first, second, and third lens units during zooming from a wide-angle end to a telephoto end and a focal length of the entire zoom lens at the wide-angle end are appropriately set.

Abstract: A zoom lens including: 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, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power in this order from an object side to an image side. During zooming, the lens units move such that an interval between adjacent lens units varies. The third lens unit includes at least two positive lenses. A partial dispersion ratio (?gF3P) of a material and the Abbe number (?d3P) of a positive lens included in the third lens unit satisfy the following conditional expressions, ?gF3P?(?1.665×10?7·?d3P3+5.213×10?5·?d3P2?5.656×10?3·?d3P+0.737)>0 50.0<?d3P<100.0.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, a fourth lens unit having negative refractive power, and a fifth lens unit having positive refractive power. At least the first, second, and third lens units move during zooming so that the first lens unit is located closer to an object side than an image side, the second lens unit is located closer to the image side, and the third lens unit is located closer to the object side at a telephoto end than a wide-angle end. Movement, focal length, and positioning parameters of first to third lens units, during zooming from the wide-angle end toward the telephoto end, are appropriately set based on mathematical conditions.

Abstract: A zoom lens includes, a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a reflective element, and a rear lens group including two or more lens units and an aperture stop, in which the first lens unit, the second lens unit, and two or more lens units of the rear lens group are moved while the reflective element is stationary during zooming, wherein movement amounts M1 and M2 of the first and second lens units during zooming, a movement amount Ms of the aperture stop, and focal lengths fw and ft of the entire zoom lens at the wide-angle end and the telephoto end, respectively, lateral magnifications ?2w and ?2t of the second lens unit, a distance LSw from the first lens surface to the aperture stop at the wide-angle end are appropriately set.

Abstract: Provided is a zoom lens system including, in order from an object side to an image side: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a prism for bending an optical path; and a rear group including a plurality of lens units, in which the first lens unit is moved to the object side while the second lens unit is moved to the image side with respect to an imaging plane at a telephoto end compared to at a wide angle end, and movement amounts M1 and M2 of the first lens unit and the second lens unit with respect to an image plane in zooming from the wide angle end to the telephoto end, a focal length f2 of the second lens unit, and a focal length ft of an entire system at the telephoto end are respectively set appropriately.

Abstract: A zoom lens includes a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a third lens unit of a positive refractive power, and a rear lens group including one or more lens units in order from an object side to an image side, the first, second, and third lens units being moved towards an object side during zooming from a wide-angle end to a telephoto end with respect to an image plane, wherein the first lens unit includes a positive lens and a negative lens, and movement amounts of the first, second, and third lens units during zooming from a wide-angle end to a telephoto end and a focal length of the entire zoom lens at the wide-angle end are appropriately set.

Abstract: A zoom lens includes, in order from the object side to the image side, a positive refractive first lens unit, a negative refractive second lens unit, a positive refractive third lens unit, and a rear group including one or more lens units. The first lens unit consists of a negative lens and a positive lens. The first to third lens units and the lens units constituting the rear group move at a time of zooming. The first and third lens units move relative to the image plane in such a way that their respective positions at the telephoto end are displaced toward the object side from their respective positions at the wide angle end. The focal lengths f1, f2 of the first and second lens units and the focal lengths fw, ft of the whole system at the wide angle end and at the telephoto end are arranged appropriately.

Abstract: A zoom lens includes, a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a reflective element, and a rear lens group including two or more lens units and an aperture stop, in which the first lens unit, the second lens unit, and two or more lens units of the rear lens group are moved while the reflective element is stationary during zooming, wherein movement amounts M1 and M2 of the first and second lens units during zooming, a movement amount Ms of the aperture stop, and focal lengths fw and ft of the entire zoom lens at the wide-angle end and the telephoto end, respectively, lateral magnifications ?2w and ?2t of the second lens unit, a distance LSw from the first lens surface to the aperture stop at the wide-angle end are appropriately set.

Abstract: A zoom lens includes a first, third and fourth lens group of positive refracting power, a second lens group of negative refracting power, wherein, during zooming from a wide-angle end to a telephoto end, at least the first lens group moves, wherein the third lens group includes, a first lens sub-group of positive refracting power and a second lens sub-group of negative refracting power, wherein the second lens sub-group includes a single negative lens, wherein the first lens sub-group of the third lens group is moved in a direction having a perpendicular component relative to an optical axis to correct image blur to be produced when the zoom lens vibrates, and wherein, when a focal length of the first lens group is denoted by f1 and the focal length of the whole system at the wide-angle end is denoted by fw, a conditional expression 11.962?f1/fw<20.0 is satisfied.

Abstract: A zoom lens includes, in order from an object side to an image side, first and second lens units respectively having positive and negative refractive powers, a reflecting prism for bending an optical path, and a rear lens group including lens units. At least the first and second lens units move for zooming. During retraction into a storage state, the prism moves to a position different from a position in an image taking state, and at least a part of the first and second lens units is retracted into a space formed by movement of the prism. Thicknesses of the first and second lens units, a moving amount of the first lens unit during zooming from a wide angle end to a telephoto end, a focal length of the first lens unit, and a focal length of the entire zoom lens at the telephoto end are set properly.