Abstract: An optical system includes a first lens unit that has positive refractive power, a second lens unit that moves during focusing and that has positive refractive power or negative refractive power, and a third lens unit that has positive refractive power or negative refractive power. The first lens unit, the second lens unit, and the third lens unit are disposed in that order from an object side to an image side. During focusing, an interval between adjacent lens units changes. In the optical system, a focal length f of the entire optical system, a distance LD along an optical axis from a lens surface of the first lens unit that is closest to the object side to an image plane, and focal lengths of positive and negative lenses that are included in the first lens unit are appropriately set.

Abstract: Provided is a zoom lens, including, in order from an object side to an image side: a first lens unit to a fourth lens unit having negative, positive, negative, and negative refractive powers; and a rear lens group. In the zoom lens, an interval between each pair of adjacent lens units is changed during zooming, the rear lens group has a positive refractive power over an entire zoom range, the third lens unit is configured to move in an optical axis direction during focusing, and each of a focal length of the zoom lens at a wide angle end (fw), and a focal length of the third lens unit (f3) is appropriately set.

Abstract: Provided is a zoom lens, including, in order from an object side to an image side: a first lens unit to a fourth lens unit having negative, positive, negative, and negative refractive powers; and a rear lens group. In the zoom lens, an interval between each pair of adjacent lens units is changed during zooming, the rear lens group has a positive refractive power over an entire zoom range, the third lens unit is configured to move in an optical axis direction during focusing, and each of a focal length of the zoom lens at a wide angle end (fw), and a focal length of the third lens unit (f3) is appropriately set.

Abstract: A conversion lens having a negative refractive power includes a positive lens GP. The positive lens GP satisfies all the following conditional expressions: 30??d?40, 1.225?[nd?(14.387/?d)]?1.276, and 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d is an Abbe number of the positive lens GP, ?gF is a partial dispersion ratio of the positive lens GP for g-line and F-line, and nd is a refractive index of the positive lens GP for d-line.

Abstract: An optical system includes an optical element. When the optical element is disposed on a magnification side with respect to an intersection point between an optical axis and a chief paraxial ray, the optical element is a positive lens. When the optical element is disposed on a reduction side with respect to the intersection point, the optical element is a negative lens. The optical element satisfies all of the following conditional expressions: 30??d?40 1.225?[nd?(14.387/?d)]?1.276 0.4300?[?gF?(2.9795/?d)]?0.5010 where ?d is Abbe number of the optical element, ?gF is a partial dispersion ratio of the optical element for g-line and F-line, and nd is a refractive index of the optical element for d-line.

Abstract: An optical system includes a negative lens satisfying the following conditional expressions: 30??d?40, 1.225?[nd?(14.387/?d)]?1.276, and 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d is an Abbe number of the negative lens, ?gF is a partial dispersion ratio of the negative lens at a g-line and an F-line, and nd is a refractive index of the negative lens at a d-line.

Abstract: An optical system used in an imaging apparatus includes an optical element. In a case where the optical element is disposed on a magnification side with respect to an intersection point of an optical axis and a chief paraxial ray, the optical element is a negative lens, and in a case where the optical element is disposed on a reduction side with respect to the intersection point, the optical element is a positive lens. The optical element is configured to satisfy all of the following conditional expressions: 30??d?40 1.225?[nd?(14.387/?d)]?1.276 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d represents an Abbe number of the optical element, ?gF is a partial dispersion ratio of the optical element for g-line and F-line, and nd is a refractive index of the optical element for d-line.

Abstract: An optical system includes a first lens unit that has positive refractive power, a second lens unit that moves during focusing and that has positive refractive power or negative refractive power, and a third lens unit that has positive refractive power or negative refractive power. The first lens unit, the second lens unit, and the third lens unit are disposed in that order from an object side to an image side. During focusing, an interval between adjacent lens units changes. In the optical system, a focal length f of the entire optical system, a distance LD along an optical axis from a lens surface of the first lens unit that is closest to the object side to an image plane, and focal lengths of positive and negative lenses that are included in the first lens unit are appropriately set.

Abstract: A lens apparatus that includes an optical system including a positive lens, the lens apparatus including a holding member arranged to hold the positive lens, an exterior member arranged to accommodate the holding member, and an engaging mechanism arranged to engage the holding member and the exterior member to each other.

Abstract: An optical system includes a first lens unit that has a positive refractive power; a second lens unit that is arranged to move during focusing and has a positive or negative refractive power; and a third lens unit that has a positive or negative refractive power. The first lens unit, the second lens unit, and the third lens unit are disposed in that order from an object side to an image side. During the focusing, an interval between adjacent lens units changes. In the optical system, a focal length f of the entire optical system, a distance LD along an optical axis from a lens surface of the first lens unit that is closest to the object side to an image plane, a material of positive lenses included in the first lens unit, and an arrangement of the positive lenses included in the first lens unit are appropriately set.

Abstract: In an optical system which includes a positive lens Gp and in which a distance on an optical axis from an object-side lens surface of a lens disposed closest to an object side to an image surface is shorter than a focal length of an entire system, an arrangement and a material of the positive lens Gp, and an arrangement of a focus unit are set appropriately.

Abstract: An optical system includes a plurality of lenses. The distance from the object side lens surface of a lens arranged an the most object side to the image plane is longer than the focal length of the entire system. The material of a positive lens G1p arranged on the most object side among positive lenses included in the optical system, and the arrangement and material of a negative lens Gn located on the most object side among negative lenses arranged an the image side of the positive lens G1p are appropriately set.

Abstract: Provided is an optical system including, in order from an object side to an image side: a first lens unit having a positive refractive power; an aperture stop; and a second lens unit having a negative refractive power, the second lens unit including: a focusing lens sub-unit which is moved on an optical axis during focusing; and an image stabilizing lens sub-unit, which is arranged between the focusing lens sub-unit and an image plane, and is moved in a direction having a component orthogonal to the optical axis during image stabilization, in which the configuration of the first lens unit, a focal length of the entire system, and a distance between the first lens unit and the second lens unit on the optical axis when focused at infinity are each appropriately set.

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; a fourth lens unit having a positive refractive power; and a fifth lens unit having a negative refractive power, in which: at a telephoto end as compared to a wide angle end, an interval between first lens unit and second lens unit is increased, and an interval between second lens unit and third lens unit is decreased; an interval between each pair of adjacent lens units is changed during zooming; and focal lengths of a focusing mechanism and the third lens unit, a movement amount of the fifth lens unit during zooming from the wide angle end to the telephoto end, and other factors are appropriately set.

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; a fourth lens unit having a positive refractive power; and a fifth lens unit having a negative refractive power, in which: at a telephoto end as compared to a wide angle end, an interval between first lens unit and second lens unit is increased, and an interval between second lens unit and third lens unit is decreased; an interval between each pair of adjacent lens units is changed during zooming; and focal lengths of a focusing mechanism and the third lens unit, a movement amount of the fifth lens unit during zooming from the wide angle end to the telephoto end, and other factors are appropriately set.

Abstract: Provided is a zoom lens, including, in order from an object side to an image side: a first lens unit to a fourth lens unit having negative, positive, negative, and negative refractive powers; and a rear lens group. In the zoom lens, an interval between each pair of adjacent lens units is changed during zooming, the rear lens group has a positive refractive power over an entire zoom range, the third lens unit is configured to move in an optical axis direction during focusing, and each of a focal length of the zoom lens at a wide angle end (fw), and a focal length of the third lens unit (f3) is appropriately set.

Abstract: A zoom lens includes, in order from an object side to an image side, first to third lens units having negative, positive, and negative refractive power, respectively, and a rear lens group including a plurality of lens units and having overall positive refractive power, a distance between every adjacent lens unit included in the zoom lens is variable during zooming. The second lens unit moves in a direction nonparallel to an optical axis during image shake correction, the third lens unit moves in an optical axis direction during focusing, each of the second and third lens units consists of a single lens element, and a focal length of the entire zoom lens at a wide-angle end, a focal length of the second lens unit, and a focal length of the third lens unit are appropriately set.

Abstract: A zoom lens includes, in order from an object side to an image side, first to third lens units having negative, positive, and negative refractive power, respectively, and a rear lens group including a plurality of lens units and having overall positive refractive power, a distance between every adjacent lens unit included in the zoom lens is variable during zooming. The second lens unit moves in a direction nonparallel to an optical axis during image shake correction, the third lens unit moves in an optical axis direction during focusing, each of the second and third lens units consists of a single lens element, and a focal length of the entire zoom lens at a wide-angle end, a focal length of the second lens unit, and a focal length of the third lens unit are appropriately set.

Abstract: An optical system includes, in order from an object side to an image side, a first lens having a negative refractive power and having a meniscus shape whose surface on the object side has a convex shape and whose surface on the image side has an aspheric shape, a second lens having a negative refractive power, and a third lens having a negative refractive power. In the optical system, a focal length of the entire optical system (f), a focal length of the first lens (f1), and respective radii of curvature of lens surfaces of the second lens on the object side and on the image side (G2R1, G2R2) satisfy the following conditions: ?1.6<f1/f<?1.2 0.1<(G2R1?G2R2)/(G2R1+G2R2)<0.5.

Abstract: An optical system includes, in order from an object side to an image side, a first lens having a negative refractive power and having a meniscus shape whose surface on the object side has a convex shape and whose surface on the image side has an aspheric shape, a second lens having a negative refractive power, and a third lens having a negative refractive power. In the optical system, a focal length of the entire optical system (f), a focal length of the first lens (f1), and respective radii of curvature of lens surfaces of the second lens on the object side and on the image side (G2R1, G2R2) satisfy the following conditions: ?1.6<f1/f<?1.2 0.1<(G2R1?G2R2)/(G2R1+G2R2)<0.5.