A zoom lens consists of four or more lens units including, in order from an object side to an image side, first, second, and third lens units having positive, negative, and positive refractive powers, respectively. During zooming from a wide-angle end to a telephoto end, the first lens unit moves, a distance between the first lens unit and the second lens unit is widened, and a distance between the second lens unit and the third lens unit is narrowed. The first lens unit consists of a single positive lens, the second lens unit includes three single lens elements, each having a negative refractive power, arranged continuously in order from the object side to the image side, predetermined conditions are satisfied.

A zoom optical system comprises a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a succeeding lens group, which are arranged in order from an object side. During zooming, distances between adjacent lens groups change, and the first lens group is fixed with respect to an image surface. During zooming from a wide angle end state to a telephoto end state, the third lens group moves toward an image surface. The succeeding lens group includes a last lens group arranged to be nearest to the image surface. Further, the following conditional expression is satisfied.

[00001]$-10.00<f3/\left(-\mathrm{fE}\right)<3.50,$ where f3 represents a focal length of the third lens group, and fE represents a focal length of the last lens group.

This optical system (OL) has a first lens group (G1) having positive refractory power, a second lens group (G2), a third lens group (G3), and a fourth lens group (G4) which are aligned in order from an object side along an optical axis, wherein when focused from an infinity object to a short-distance object, the second lens group (G2) and the third lens group (G3) move in mutually different trajectories along the optical axis, and the second lens group (G2) and the third lens group (G3) are composed of three or less lenses in total.

A zoom optical system comprises a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a succeeding lens group, which are arranged in order from an object side. During zooming, distances between adjacent said lens groups change. The succeeding lens group comprises a first focusing lens group having a negative refractive power which is moved during focusing, and a second focusing lens group having a positive refractive power which is moved during focusing, which are arranged in order from an object side. Further, the following conditional expression is satisfied:
0.80<(fF1)/fF2<5.00, where fF1 represents a focal length of the first focusing lens group, and fF2 represents a focal length of the second focusing lens group.

An optical imaging lens includes a first lens element, a second lens, an aperture stop, a third lens element and a fourth lens element from an object side to an image side in order along an optical axis, and each lens element has an object-side surface and an image-side surface. An optical axis of the image-side surface of the first lens element is convex and an optical axis of the image-side surface of the fourth lens element is concave. HFOV stands for the half field of view of the entire optical imaging lens and TTL is a distance from the object-side surface of the first lens element to an image plane along the optical axis to satisfy HFOV/TTL1.500 /mm.

A zoom lens 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 third lens unit having positive refractive power, and a rear group. A distance between adjacent lens units changes during zooming from a wide-angle end to a telephoto end. The first lens unit is fixed relative to an image plane during zooming from the wide-angle end to the telephoto end. The first lens unit includes single lens having negative refractive power closest to an object, and a plurality of lenses having positive refractive powers disposed on the image side of the single lens. An air lens is formed by an air gap between the single lens and a lens adjacent to and disposed on the image side of the single lens. A predetermined inequality is satisfied.

An optical lens, in order from an object side to an image-forming side, includes: a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having negative refractive power, a sixth lens having negative refractive power, a seventh lens having negative refractive power and an eighth lens having refractive power.

A zoom optical system comprises a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a succeeding lens group, which are arranged in order from an object side. During zooming, distances between adjacent said lens groups change. The succeeding lens group comprises a first focusing lens group having a negative refractive power which is moved during focusing, and a second focusing lens group having a positive refractive power which is moved during focusing, which are arranged in order from an object side. Further, the following conditional expression is satisfied:

[00001]$0.80<\left(-\mathrm{fF}1\right)/\mathrm{fF}2<5.,$ where fF1 represents a focal length of the first focusing lens group, and fF2 represents a focal length of the second focusing lens group.

A zoom lens 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 third lens unit having positive refractive power, and a rear group. A distance between adjacent lens units changes during zooming from a wide-angle end to a telephoto end. The first lens unit is fixed relative to an image plane during zooming from the wide-angle end to the telephoto end. The first lens unit includes single lens having negative refractive power closest to an object, and a plurality of lenses having positive refractive powers disposed on the image side of the single lens. An air lens is formed by an air gap between the single lens and a lens adjacent to and disposed on the image side of the single lens. A predetermined inequality is satisfied.