The lens apparatus includes an optical system, a voltage transformation unit, and an actuator. A first lens unit of the optical system is moved toward the object side during zooming from a wide-angle end to a telephoto end. The voltage transformation unit includes coils. The actuator is configured to be driven by a voltage output from the voltage transformation unit and to move a part of the lens units in the optical system during focusing. The coil is disposed at a position that is separated from a position of a most object-side surface of the optical system at the wide-angle end, toward the image side by a maximum or more moving amount of the first lens unit, and is closer to the object side than a most image-side surface of the optical system at the wide-angle end.

A zoom optical system comprising, in order from an object side: a first lens group (G1) having positive refractive power; a front-side lens group; an intermediate lens group having positive refractive power; and a rear-side lens group. The front-side lens group is composed of one or more lens groups and has a negative lens group. At least part of the intermediate lens group is a focusing lens group. The rear-side lens group is composed of one or more lens groups. Upon zooming, the first lens group and the intermediate lens group are moved with respect to an image surface, a distance between the first lens group and the front-side lens group is changed, and a distance between the intermediate lens group and the rear-side lens group is changed. The following conditional expression is satisfied:

0.000<Fw<0.800 where Fw denotes a lateral magnification of the focusing lens group in the wide-angle end state.

Provided is an optical device including an optics including at least two moving groups that are movable along an optical axis and share portions of driving regions; a plurality of actuators configured to move the at least two moving groups along the optical axis, respectively; and a control unit configured to control the positions of the at least two moving groups by operating the actuators, wherein the control unit moves the at least two moving groups independently, such that the position coordinates of the at least two moving groups in one integrated coordinates system do not coincide with each other.

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 and configured to move for zooming; and at least one lens unit configured to move for zooming. The distance between each pair of the lens units adjacent to each other is changed for zooming. The first lens unit includes a negative lens and an Abbe number and a partial dispersion ratio of the negative lens are properly determined.

A zoom lens consists of a positive first lens group that is fixed during zooming, a negative second lens group that moves during zooming, a positive third lens group that moves during zooming, a positive fourth lens group that moves during zooming, and a positive fifth lens group that is fixed during zooming. During zooming from a wide angle end to a telephoto end, the fourth lens group moves from an image side to an object side, the second lens group and a composite group consisting of the third lens group and the fourth lens group pass through points where respective lateral magnifications are 1 at the same time, the fifth lens group consists of a negative fifth A lens group that moves during anti-shake operation, and a positive fifth B lens group that is fixed during the anti-shake operation, and the lateral magnification of the fifth A lens group is negative.

A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having positive refractive power, a fifth lens group (G5) are arranged in order from an object, and a distance between the first lens group (G1) and the second lens group (G2), a distance between the second lens group (G2) and the third lens group (G3), a distance between the third lens group (G3) and the fourth lens group (G4), and a distance between the fourth lens group (G4) and the fifth lens group (G5) change upon zooming, and a lens group arranged closest to an image is approximately fixed against an image surface (I) upon zooming, and the third lens group (G3) moves along the optical axis upon focusing, and the following expression (1) is satisfied.

0.480<f3/ft<4.000 (1)

A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power are arranged in order from an object, and zooming is performed by changing distances between each lens group, and the first lens group (G1) is composed of three or more lenses, the fourth lens group (G4) is composed of two or less lenses, and the fifth lens group (G5) is composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and the following conditional expression (1) is satisfied.
8.40<f1/(f2)(1) where, f1 denotes a focal length of the first lens group (G1), and f2 denotes a focal length of the second lens group (G2).

This disclosure describes a videoconferencing system that includes a lens housing having a longitudinal axis; a lens assembly disposed within the lens housing along the longitudinal axis and comprising from front to rear: first, second, third, fourth and fifth lens groups. The lens groups are aligned with and distributed along the longitudinal axis. The videoconferencing system also includes a first motor coupled to and configured to move the second lens group along the longitudinal axis between the first and third lens groups; and a second motor coupled to and configured to move the fourth lens group along the longitudinal axis between the third and fifth lens groups.

A zoom lens includes, in order from an object side to an image side, first, second and third lens units having positive, negative and positive refractive powers. The first lens unit moves during zooming. During zooming from a wide-angle end to a telephoto end, a distance between the first and second lens units widens, and a distance between the second and third lens units narrows. The first lens unit consists of three or less lenses. The second lens unit consists of, in order from the object side to the image side, a first single lens as a spherical lens having a negative refractive power, a cemented lens in which a lens having a negative refractive power and a lens having a positive refractive power are cemented, and a second single lens as a spherical lens having a negative refractive power. A predetermined condition is satisfied.

A zoom lens consists of, in order from the object side to the image side, a first lens unit having a positive refractive power and configured not to be moved for zooming, a second lens unit having a negative refractive power and configured to be moved for zooming, and a rear lens group including at least one lens unit. The first lens unit includes at least six lenses, a lens closest to the object side included in the first lens unit is a negative lens, and the zoom lens satisfies conditional expressions: 1.65<f1n/f1<1.10; 37<1n<48; and 87<pave<100, where f1n is a focal length of the negative lens, 1n is an Abbe number of the negative lens with respect to d-line, f1 is a focal length of the first lens unit, and pave is an average of Abbe numbers of positive lenses included in the first lens unit with respect to d-line.