A freeform varifocal optical assembly includes at least three optical modules including a first plurality of optical elements including Pancharatnam-Berry phase (PBP) lenses, polarization sensitive hologram (PSH) lenses, metamaterials, or combinations thereof. The plurality of optical elements of each optical module include a property associated with a Zernike polynomial. Each of the first and the three optical modules are configurable between a plurality of optical powers. The freeform varifocal optical assembly is configurable to output a predetermined wavefront in response to an input wavefront.

A zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the first lens group and the fifth lens group are not moved, and the second lens group, the third lens group, and the fourth lens group are moved. The first lens group consists of one negative lens and five positive lenses in order from the object side to an image side. Predetermined conditional expressions related to a refractive index, an Abbe number, and a partial dispersion ratio of the negative lens of the first lens group are satisfied.

A zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the first lens group and the fifth lens group are not moved, and the second lens group, the third lens group, and the fourth lens group are moved. The first lens group consists of one negative lens and five positive lenses in order from the object side to an image side. Predetermined conditional expressions related to a refractive index, an Abbe number, and a partial dispersion ratio of the negative lens of the first lens group are satisfied.

A variable power optical system (ZL (1)) includes a plurality of lens groups (G1-G7). During variable magnification, an interval between adjacent lens groups changes. The plurality of lens groups include: a first focusing lens group (G5) that moves during focusing; and a second focusing lens group (G6) that is disposed more toward an imaging surface side than the first focusing lens group and that moves along a different trajectory than the first focusing lens group during focusing. The first focusing lens group and the second focusing lens group both have a negative refractive power. The plurality of lens groups satisfy the following condition: 0.40<fF1/fF2<3.50 (wherein fF1 is the focal distance of the first focusing lens group, and fF2 is the focal distance of the second focusing lens group).

A variable power optical system (ZL (1)) includes a plurality of lens groups (G1-G7). During variable magnification, an interval between adjacent lens groups changes. The plurality of lens groups include: a first focusing lens group (G5) that moves during focusing; and a second focusing lens group (G6) that is disposed more toward an imaging surface side than the first focusing lens group and that moves along a different trajectory than the first focusing lens group during focusing. The first focusing lens group and the second focusing lens group both have a negative refractive power. The first focusing lens group or the second focusing lens group includes at least one lens having a positive refractive power, and is configured so as to satisfy the following condition: 1.40<fFP/(−fFN)<3.50 (wherein fFP is the focal distance of a lens with the strongest positive refractive power in the first focusing lens group or the second focusing lens group, and fFN is the focal distance of a lens with the strongest negative refractive power in the first focusing lens group or the second focusing lens group).

A variable power optical system (ZL (1)) includes a plurality of lens groups (G1-G7). During variable magnification, an interval between adjacent lens groups changes. The plurality of lens groups include: a first focusing lens group (G5) that moves during focusing; and a second focusing lens group (G6) that is disposed more toward an imaging surface side than the first focusing lens group and that moves along a different trajectory than the first focusing lens group during focusing. The first focusing lens group and the second focusing lens group both have a negative refractive power. The first focusing lens group or the second focusing lens group includes at least one lens having a positive refractive power, and is configured so as to satisfy the following condition: 1.40<fFP/(−fFN)<3.50 (wherein fFP is the focal distance of a lens with the strongest positive refractive power in the first focusing lens group or the second focusing lens group, and fFN is the focal distance of a lens with the strongest negative refractive power in the first focusing lens group or the second focusing lens group).

A lens apparatus includes two optical systems. Each of the two optical systems 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 first reflective surface, a second reflective surface, and a rear lens unit having positive refractive power. At least a distance between the first lens unit and the second lens unit and a distance between the second lens unit and the first reflective surface are changed during magnification variation. A predetermined condition is satisfied.

A lens apparatus includes two optical systems. Each of the two optical systems 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 first reflective surface, a second reflective surface, and a rear lens unit having positive refractive power. At least a distance between the first lens unit and the second lens unit and a distance between the second lens unit and the first reflective surface are changed during magnification variation. A predetermined condition is satisfied.

A freeform varifocal optical assembly includes at least three optical modules including a first plurality of polarization sensitive optical elements including Pancharatnam-Berry phase (PBP) lenses, polarization sensitive hologram (PSH) lenses, metamaterials, or combinations thereof. The plurality of polarization sensitive optical elements of each optical module include a property associated with a Zernike polynomial. Each of the first and the three optical modules are configurable between a plurality of optical powers. The freeform varifocal optical assembly is configurable to output a predetermined wavefront in response to an input wavefront.

A freeform varifocal optical assembly includes at least three optical modules including a first plurality of polarization sensitive optical elements including Pancharatnam-Berry phase (PBP) lenses, polarization sensitive hologram (PSH) lenses, metamaterials, or combinations thereof. The plurality of polarization sensitive optical elements of each optical module include a property associated with a Zernike polynomial. Each of the first and the three optical modules are configurable between a plurality of optical powers. The freeform varifocal optical assembly is configurable to output a predetermined wavefront in response to an input wavefront.