A zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power, a middle group that includes a plurality of lens groups in which the spacings between adjacent lens groups change during zooming, and the final lens group. The focusing group that moves during focusing is disposed in the middle group. The zoom lens satisfies predetermined conditional expressions.

A projection lens includes a plurality of lens units, and a diaphragm, wherein in a case where a lens unit that moves in an optical axis direction of the projection lens during focusing serves as a focus lens unit among the plurality of lens units, at least one lens included in a lens unit that is different from the focus lens unit among the plurality of lens units and is disposed more towards a reduction conjugate side than the diaphragm is configured to move in the optical axis direction when an amount of field curvature is adjusted to focus on a curved projection surface, and wherein when the amount of field curvature is adjusted, both the at least one lens and the focus lens unit move in the optical axis direction.

A projection lens includes a plurality of lens units, and a diaphragm, wherein in a case where a lens unit that moves in an optical axis direction of the projection lens during focusing serves as a focus lens unit among the plurality of lens units, at least one lens included in a lens unit that is different from the focus lens unit among the plurality of lens units and is disposed more towards a reduction conjugate side than the diaphragm is configured to move in the optical axis direction when an amount of field curvature is adjusted to focus on a curved projection surface, and wherein when the amount of field curvature is adjusted, both the at least one lens and the focus lens unit move in the optical axis direction.

A zoom optical system consists of a first lens group having negative refractive power, a second lens group having positive refractive power, and a rear lens group which are disposed in order from an object. The rear lens group comprises a last lens group and an F lens group in order from a side closest to an image. Lens groups forming the first lens group, the second lens group, and the rear lens group are configured in such a manner that, upon zooming, the respective lens groups move and a distance between the lens groups adjacent to each other changes. At least a part of the F lens group is configured to move upon focusing. Further, the following conditional expression is satisfied.
−0.220<f1/fE<0.280
where f1: a focal length of the first lens group, and fE: a focal length of the last lens group

A zoom optical system consists of a first lens group having negative refractive power, a second lens group having positive refractive power, and a rear lens group which are disposed in order from an object. The rear lens group comprises a last lens group and an F lens group in order from a side closest to an image. Lens groups forming the first lens group, the second lens group, and the rear lens group are configured in such a manner that, upon zooming, the respective lens groups move and a distance between the lens groups adjacent to each other changes. At least a part of the F lens group is configured to move upon focusing. Further, the following conditional expression is satisfied.
−0.220<f1/fE<0.280
where f1: a focal length of the first lens group, and fE: a focal length of the last lens group

A zoom optical system consists of, in order from an object on an optical axis: a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a rear group that includes a plurality of lens groups. The rear group comprises a first focusing lens group having a positive refractive power, and a second focusing lens group having a negative refractive power. Upon zooming from a wide angle end to a telephoto end, distances between lens groups adjacent to each other among the first lens group, the second lens group, and the plurality of lens groups, change. Upon focusing from an infinity object to a short distance object, the first focusing lens group and the second focusing lens group move toward an image along movement trajectories different from each other. The following conditional expression is satisfied,

1.10<f2/fF2<2.00

where f2: a focal length of the second lens group, and

fF2: a focal length of the second focusing lens group.

A zoom optical system consists of, in order from an object on an optical axis: a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a rear group that includes a plurality of lens groups. The rear group comprises a first focusing lens group having a positive refractive power, and a second focusing lens group having a negative refractive power. Upon zooming from a wide angle end to a telephoto end, distances between lens groups adjacent to each other among the first lens group, the second lens group, and the plurality of lens groups, change. Upon focusing from an infinity object to a short distance object, the first focusing lens group and the second focusing lens group move toward an image along movement trajectories different from each other. The following conditional expression is satisfied,

1.10<f2/fF2<2.00

where f2: a focal length of the second lens group, and

fF2: a focal length of the second focusing lens group.

A converter lens has negative refractive power, and is disposed on an image side of a master lens so that a focal length of an entire system becomes greater than a focal length of the master lens alone. The converter lens includes a first lens element closest to an object and a second lens element next to an image side of the first lens element with a space between the first lens element and the second lens element. A focal length of the converter lens, a focal length of an air lens formed by the first lens element and the second lens element, the shape of an image-side lens surface of the first lens element, and the shape of an object-side lens surface of the second lens element are determined as appropriate.

A converter lens has negative refractive power, and is disposed on an image side of a master lens so that a focal length of an entire system becomes greater than a focal length of the master lens alone. The converter lens includes a first lens element closest to an object and a second lens element next to an image side of the first lens element with a space between the first lens element and the second lens element. A focal length of the converter lens, a focal length of an air lens formed by the first lens element and the second lens element, the shape of an image-side lens surface of the first lens element, and the shape of an object-side lens surface of the second lens element are determined as appropriate.

Provided is a zoom lens including, 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; a fifth lens unit having a positive refractive power; a sixth lens unit having a negative refractive power; a seventh lens unit having a positive refractive power; and an eighth lens unit having a negative refractive power, in which an interval between each pair of adjacent lens units is changed for zooming.