Abstract: In an optical system, a height from an optical axis of a paraxial marginal ray that passes through a lens surface closest to an object is smaller than a maximum height from the optical axis of the paraxial marginal ray that passes through a lens surface on an image side of an intersection between the optical axis and a paraxial chief ray. The optical system includes an optical element disposed on an object side or the image side of the intersection. The optical element has positive refractive power in a case where the optical element is disposed on the object side of the intersection, and has negative refractive power in a case where the optical element is disposed placed on the image side of the intersection. A predetermined condition is satisfied.

Abstract: An optical system includes an optical element having negative refractive power and disposed on at least one of an object side and an image side of an intersection of an optical axis and a pupil paraxial ray. The optical element is made of a glass material and satisfies a predetermined condition.

Abstract: A zoom lens including, in order from object side to image side, first to fourth lens units respectively having positive, negative, positive, and positive refractive powers. During zooming from a wide-angle end to a telephoto end, the first lens unit is arranged to move, the distance between the first lens unit and the second lens unit increases, the distance between the second lens unit and the third lens unit decreases, and the distance between the third lens unit and the fourth lens unit decreases. The second lens unit consists of a first lens having a negative refractive power and a second lens having a positive refractive power, the second lens being disposed on the image side of the first lens. A predetermined condition is satisfied.

Abstract: An optical system includes an object side lens unit arranged closest to an object, immobilized in focusing, and having a positive refractive power, an image plane side lens unit arranged closest to an image plane and having a negative refractive power, and a first focus lens unit and a second focus lens unit which are arranged between the object side lens unit and the image plane side lens unit and are moved in focusing. The object side lens unit consists of a first partial unit having the negative refractive power, a second partial unit having the positive refractive power, a third partial unit having the positive or the negative refractive power which are arranged in order from an object side to an image plane side. The second partial unit is moved in a direction including a component in a perpendicular direction to an optical axis in image blur correction.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit with a positive refractive power, a second lens unit with a negative refractive power, a third lens unit with a positive refractive power, and a fourth lens unit with a positive refractive power. During zooming from a wide-angle end to a telephoto end, the first lens unit moves, the second lens unit is fixed, a distance between the first lens unit and the second lens unit is widened, a distance between the second lens unit and the third lens unit is narrowed, and a distance between the third lens unit and the fourth lens unit is narrowed. The first lens unit includes a positive lens and a negative lens. Each of the second, third, and fourth lens units consists of two lenses or less.

Abstract: An optical system includes a first lens unit having positive refractive power, a second lens unit, and a third lens unit having negative refractive power arranged in order from an object side to an image side. The second lens unit moves in focusing, thereby changing a distance between adjacent lens units. The first lens unit includes a positive lens, and the third lens unit includes a negative lens. A focal length of the positive lens, a focal length of the negative lens, a focal length of the third lens unit, and a back focus of the optical system are appropriately set.

Abstract: A zoom lens including, in order from object side to image side, first to fourth lens units respectively having positive, negative, positive, and positive refractive powers. During zooming from a wide-angle end to a telephoto end, the first lens unit is arranged to move, the distance between the first lens unit and the second lens unit increases, the distance between the second lens unit and the third lens unit decreases, and the distance between the third lens unit and the fourth lens unit decreases. The second lens unit consists of a first lens having a negative refractive power and a second lens having a positive refractive power, the second lens being disposed on the image side of the first lens. A predetermined condition is satisfied.

Abstract: An optical system is constituted of a first lens unit having a positive refractive power, a second lens unit having a positive refractive power and moving when focusing is performed, and a third lens unit which are arranged in this order from an object side to an image side, and distances between neighboring lens units are changed when focusing is performed. In the optical system, a back focus, arrangement of the second lens unit, and the like are appropriately set.

Abstract: An optical system includes a first lens unit B1 having a positive refractive power, a second lens unit B2, and a third lens unit B3 disposed in order from an object side to an image side. The second lens unit B2 moves in focusing so that an interval between adjacent lens units among the first, second, and third lens units changes. The first lens unit B1 includes a positive lens G1p disposed closest to the object side and a negative lens G1n being a closest negative lens with respect to the object side. The optical system satisfies a predetermined condition.

Abstract: An optical system includes an object side lens unit arranged closest to an object, immobilized in focusing, and having a positive refractive power, an image plane side lens unit arranged closest to an image plane and having a negative refractive power, and a first focus lens unit and a second focus lens unit which are arranged between the object side lens unit and the image plane side lens unit and are moved in focusing. The object side lens unit consists of a first partial unit having the negative refractive power, a second partial unit having the positive refractive power, a third partial unit having the positive or the negative refractive power which are arranged in order from an object side to an image plane side. The second partial unit is moved in a direction including a component in a perpendicular direction to an optical axis in image blur correction.

Abstract: An optical system is constituted of a first lens unit having a positive refractive power, a second lens unit having a positive refractive power and moving when focusing is performed, and a third lens unit which are arranged in this order from an object side to an image side, and distances between neighboring lens units are changed when focusing is performed. In the optical system, a back focus, arrangement of the second lens unit, and the like are appropriately set.

Abstract: An optical system includes a first lens unit having positive refractive power, a second lens unit, and a third lens unit having negative refractive power arranged in order from an object side to an image side. The second lens unit moves in focusing, thereby changing a distance between adjacent lens units. The first lens unit includes a positive lens, and the third lens unit includes a negative lens. A focal length of the positive lens, a focal length of the negative lens, a focal length of the third lens unit, and a back focus of the optical system are appropriately set.

Abstract: An optical system includes a first lens unit B1 having a positive refractive power, a second lens unit B2, and a third lens unit B3 disposed in order from an object side to an image side. The second lens unit B2 moves in focusing so that an interval between adjacent lens units among the first, second, and third lens units changes. The first lens unit B1 includes a positive lens G1p disposed closest to the object side and a negative lens G1n being a closest negative lens with respect to the object side. The optical system satisfies a predetermined condition.

Abstract: In an optical system in which a focal length of an entire system is shorter than a back focus, an image stabilizing lens unit, is at a position adjacent to an aperture on an image side and a cemented lens obtained by cementing a positive lens and a negative lens is on an object side of the aperture diaphragm, and the focal length of the entire system, a focal length of the image stabilizing lens unit, a focal length of the cemented lens, a distance on the optical axis from the aperture to a lens surface on the object side of the image stabilizing lens unit, and a distance on the optical axis from a first lens surface on a side closest to an object to a final lens surface on a side closest to an image when an infinite-distance object is brought into focus are set.

Abstract: In an optical system in which a focal length of an entire system is shorter than a back focus, an image stabilizing lens unit, is at a position adjacent to an aperture on an image side and a cemented lens obtained by cementing a positive lens and a negative lens is on an object side of the aperture diaphragm, and the focal length of the entire system, a focal length of the image stabilizing lens unit, a focal length of the cemented lens, a distance on the optical axis from the aperture to a lens surface on the object side of the image stabilizing lens unit, and a distance on the optical axis from a first lens surface on a side closest to an object to a final lens surface on a side closest to an image when an infinite-distance object is brought into focus are set.

Abstract: A zoom lens comprising sequentially from an object side a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a positive refractive power and formed by a cemented lens alone that includes a negative lens and a positive lens. The zoom lens zooms from a wide angle edge to a telephoto edge by moving the second lens group along an optical axis, from the object side toward the image plane side. The zoom lens performs focusing and corrects image plane variation accompanying zoom by moving the fourth lens group along the optical axis, and corrects image blur caused by minute vibrations by moving the entire fifth lens group in a direction orthogonal to the optical axis.

Abstract: In an optical system in which a focal length of an entire system is shorter than a back focus, an image stabilizing lens unit, is at a position adjacent to an aperture on an image side and a cemented lens obtained by cementing a positive lens and a negative lens is on an object side of the aperture diaphragm, and the focal length of the entire system, a focal length of the image stabilizing lens unit, a focal length of the cemented lens, a distance on the optical axis from the aperture to a lens surface on the object side of the image stabilizing lens unit, and a distance on the optical axis from a first lens surface on a side closest to an object to a final lens surface on a side closest to an image when an infinite-distance object is brought into focus are set.

Abstract: A zoom lens comprising sequentially from an object side a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a positive refractive power and formed by a cemented lens alone that includes a negative lens and a positive lens. The zoom lens zooms from a wide angle edge to a telephoto edge by moving the second lens group along an optical axis, from the object side toward the image plane side. The zoom lens performs focusing and corrects image plane variation accompanying zoom by moving the fourth lens group along the optical axis, and corrects image blur caused by minute vibrations by moving the entire fifth lens group in a direction orthogonal to the optical axis.