The present disclosure relates to optical lens, and provides a zoom lens including, from an object side to an image side in sequence: a first lens having a negative refractive power, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, a fifth lens group having a negative refractive power; distances between adjacent two of the first lens, the second lens, the third lens, the fourth lens and the fifth lens group are variable in the direction of the optical axis; the fifth lens group including a fifth lens having a positive refractive power and a sixth lens having a negative refractive power; wherein the zoom lens satisfies conditions of: f_Tele/f_Wide>1.8; −1.85≤f3/f2≤−1.20; and 2.00≤f4/f2≤3.00.

The present disclosure relates to optical lens, and provides a zoom lens including, from an object side to an image side in sequence: a first lens having a negative refractive power, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, a fifth lens group having a negative refractive power; distances between adjacent two of the first lens, the second lens, the third lens, the fourth lens and the fifth lens group are variable in the direction of the optical axis; the fifth lens group including a fifth lens having a positive refractive power and a sixth lens having a negative refractive power; wherein the zoom lens satisfies conditions of: f_Tele/f_Wide>1.8; −1.85≤f3/f2≤−1.20; and 2.00≤f4/f2≤3.00.

A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group. The second and third lens groups are moved during zooming. The first lens group includes a positive first sub-lens group which does not move during a focusing operation, and a positive second sub-lens group which moves during the focusing operation. The first sub-lens group includes at least one negative lens element, the second sub-lens group is a positive single lens element, and the following conditions (1) and (2) are satisfied:
60<νd1b<75   (1),
and
νd1a<24  (2),
wherein νd1b and νd1a_designates Abbe numbers at the d-line of the positive single lens element of the second sub-lens group and at the d-line of the negative lens element within the first sub-lens group, respectively.

A zoom lens is constituted by, in order from the object side: a negative first lens group; an aperture stop; a positive second lens group; a negative third lens group; and a positive fourth lens group. All of the lens groups move along the optical axis when changing magnification from the wide angle end to the telephoto end such that the distance between the first lens group and the second lens group decreases and the distance between the second lens group and the third lens group increases. The first lens group is constituted by, in order from the object side, a 1-1 lens having a negative refractive power, a 1-2 lens having a negative refractive power, and a 1-3 lens having a positive refractive power. Conditional Formula (1) below is satisfied.
1.75<ndave<1.92  (1)

A zoom lens is constituted by, in order from the object side: a negative first lens group; an aperture stop; a positive second lens group; a negative third lens group; and a positive fourth lens group. All of the lens groups move along the optical axis when changing magnification from the wide angle end to the telephoto end such that the distance between the first lens group and the second lens group decreases and the distance between the second lens group and the third lens group increases. The first lens group is constituted by, in order from the object side, a 1-1 lens having a negative refractive power, a 1-2 lens having a negative refractive power, and a 1-3 lens having a positive refractive power. Conditional Formula (1) below is satisfied.
1.75<ndave<1.92  (1)

A zoom lens system includes: a first lens group having a negative refractive power; a second lens group having a positive refractive power; and an aperture between the first and second lens groups, wherein the first lens group and the second lens group are sequentially arranged from an object side to an image side, wherein the zoom lens system performs zooming and focusing by moving the second and first lens groups, respectively, along an optical axis, and satisfies
2.5<(f.sub.w/f.sub.t)×(T.sub.w/Y)<4.5, where f.sub.w denotes an entire focal length at a wide-angle end, f.sub.t denotes an entire focal length at a telephoto end, and Tw denotes a distance between an image plane and an object side lens surface of a lens closest to the object side of the first lens group at the wide-angle end, and Y denotes a radical axis image height.

A zoom lens system includes: a first lens group having a negative refractive power; a second lens group having a positive refractive power; and an aperture between the first and second lens groups, wherein the first lens group and the second lens group are sequentially arranged from an object side to an image side, wherein the zoom lens system performs zooming and focusing by moving the second and first lens groups, respectively, along an optical axis, and satisfies
2.5<(f.sub.w/f.sub.t)×(T.sub.w/Y)<4.5, where f.sub.w denotes an entire focal length at a wide-angle end, f.sub.t denotes an entire focal length at a telephoto end, and Tw denotes a distance between an image plane and an object side lens surface of a lens closest to the object side of the first lens group at the wide-angle end, and Y denotes a radical axis image height.

An imaging lens is constituted by, in order from the object side to the image side: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a stop; and a third lens group having a positive refractive power or a negative refractive power. The first lens group has at least two positive lenses, a first positive lens from among the at least two positive lenses being positioned most toward the object side, and three negative lenses being consecutively provided adjacent to the first positive lens at the image side thereof. The first lens group is fixed with respect to an imaging surface, and focusing operations are performed by moving the second lens group and the third lens group.

A projection lens includes, in order from a magnification side to a reduction side, a first lens group having a negative refractive power, a reflector to bend an optical path, a second lens group having a positive refractive power, and an aperture stop disposed within the second lens group. The second lens group has a positive refractive power on the magnification side of the aperture stop, and a negative refractive power on the reduction side of the aperture stop. Conditional formula (A) is satisfied: (A) Ot/Y′<6.1, where Ot is a distance along the optical axis between a maximum-magnification-side surface of the first lens group and a surface of a lens adjacent to a reduction-side surface of the reflector, and Y′ is a maximum height of the image displayed on the display surface of the image display element.

Provided is a zoom lens including a plurality of lens units, in which an interval between each pair of adjacent lens units is changed for zooming. The plurality of lens units consist of, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a rear lens group including at least two lens units. The first lens unit and the second lens unit are configured to move during zooming. The first lens unit includes, in order from the object side to the image side, a negative lens G1, a negative lens G2, and a negative lens G3.