An optical system includes: a first lens group; a second lens group disposed behind the first lens group; and a third lens group disposed behind the second lens group. The optical system satisfies: 6.0<f/f2<2.0; ih/f<0.4; 0.7<TTL/f<1.0; 1.6<Fno/7.0; and Ims/dOIS>1.5 where ih: a maximum image height of the first lens group, TTL: a distance from a surface of a lens to an image forming surface, Fno: an F number of the first lens group, dOIS: an absolute value of a distance for which the second lens group is driven in the direction perpendicular to the optical axis, and Ims: an absolute value of a distance for which the image moves in the direction perpendicular to the optical axis on the image plane.

An optical system includes: a first lens group; a second lens group disposed behind the first lens group; and a third lens group disposed behind the second lens group. The optical system satisfies: 6.0<f/f2<2.0; ih/f<0.4; 0.7<TTL/f<1.0; 1.6<Fno/7.0; and Ims/dOIS>1.5 where ih: a maximum image height of the first lens group, TTL: a distance from a surface of a lens to an image forming surface, Fno: an F number of the first lens group, dOIS: an absolute value of a distance for which the second lens group is driven in the direction perpendicular to the optical axis, and Ims: an absolute value of a distance for which the image moves in the direction perpendicular to the optical axis on the image plane.

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 negative refractive power, and a rear unit including at least one lens unit. In the zoom lens, the locus of movement, the focal length, the amount of displacement during zooming, and the shapes of lens surfaces are appropriately set for each lens unit.

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 negative refractive power, and a rear unit including at least one lens unit. In the zoom lens, the locus of movement, the focal length, the amount of displacement during zooming, and the shapes of lens surfaces are appropriately set for each lens unit.

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; a second lens unit having a negative refractive power configured to move during focusing; and a third lens unit, wherein an interval between each pair of adjacent lens units is changed during focusing, wherein the first lens unit includes a positive lens arranged closest to the object side and an aperture stop, wherein the second lens unit consists of one negative lens, and wherein a distance on an optical axis from a lens surface closest to the object side in the optical system to an image plane, a focal length of the optical system, a refractive index of a material of the one negative lens, and an Abbe number of the material of the one negative lens are appropriately set.

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; a second lens unit having a negative refractive power configured to move during focusing; and a third lens unit, wherein an interval between each pair of adjacent lens units is changed during focusing, wherein the first lens unit includes a positive lens arranged closest to the object side and an aperture stop, wherein the second lens unit consists of one negative lens, and wherein a distance on an optical axis from a lens surface closest to the object side in the optical system to an image plane, a focal length of the optical system, a refractive index of a material of the one negative lens, and an Abbe number of the material of the one negative lens are appropriately set.

Provided is a zoom lens, including, in order from object side: a positive first unit; a negative second unit; a third unit having a positive or positive refractive power; and a rear group including at least one unit, in which: the first unit is not moved for zooming, and intervals between adjacent units are changed during zooming; the first unit includes three lenses, and the second unit includes three lenses; at least two lens surfaces, among lens surfaces of lenses included in the second unit except for a lens arranged closest to the object side, have aspherical shapes; and focal lengths of the zoom lens at a wide angle end and at a telephoto end, movement amounts of the second and third units during zooming from the wide angle end to the telephoto end are appropriately set.

Provided is a zoom lens, including, in order from object side: a positive first unit; a negative second unit; a third unit having a positive or positive refractive power; and a rear group including at least one unit, in which: the first unit is not moved for zooming, and intervals between adjacent units are changed during zooming; the first unit includes three lenses, and the second unit includes three lenses; at least two lens surfaces, among lens surfaces of lenses included in the second unit except for a lens arranged closest to the object side, have aspherical shapes; and focal lengths of the zoom lens at a wide angle end and at a telephoto end, movement amounts of the second and third units during zooming from the wide angle end to the telephoto end are appropriately set.

A zoom lens includes, in order from object-side, a fixed positive first group including three-or-more lenses, a negative second group including a unit moving toward image-side during zooming toward telephoto-end, a positive third group including a unit moving toward object-side during zooming from wide-end to telephoto-end, a negative fourth group moving during zooming and focusing, and a rear group. Focal lengths of the first group and the zoom lens at wide-end, a movement amount of a unit moving by largest amount during zooming toward telephoto-end in the second group, a largest value of position change between wide-end and telephoto-end of units moving toward an object side during zooming from wide-end to telephoto-end, refractive index for d-line of a positive lens closest to image-side in the first group, and average refractive index for d-line of positive lenses of the first group other than the positive lens are appropriately set.

A zoom lens includes, in order from object-side, a fixed positive first group including three-or-more lenses, a negative second group including a unit moving toward image-side during zooming toward telephoto-end, a positive third group including a unit moving toward object-side during zooming from wide-end to telephoto-end, a negative fourth group moving during zooming and focusing, and a rear group. Focal lengths of the first group and the zoom lens at wide-end, a movement amount of a unit moving by largest amount during zooming toward telephoto-end in the second group, a largest value of position change between wide-end and telephoto-end of units moving toward an object side during zooming from wide-end to telephoto-end, refractive index for d-line of a positive lens closest to image-side in the first group, and average refractive index for d-line of positive lenses of the first group other than the positive lens are appropriately set.