A zoom lens system according to the present disclosure includes a plurality of lens groups each of which is made up of at least one lens element. The zoom lens system includes, in order from an object side to an image side: a first focusing lens group having a negative power; and a second focusing lens group having a positive power, wherein when zooming is performed from a wide end to a telephoto end, the first focusing lens group and the second focusing lens group move along an optical axis, when focusing is performed from an infinity focusing state to a proximity object focusing state, the first focusing lens group and the second focusing lens group move to perform the focusing, and a predetermined condition is satisfied.

A zoom lens system includes: 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; a fourth lens group having a positive refractive power; a fifth lens group having a positive refractive power; and a sixth lens group having a positive refractive power, wherein the first to sixth lens groups are sequentially arranged along an optical axis from an object side to an image plane side, and zooming is performed by moving at least one of the second lens group, the fourth lens group and the fifth lens group along the optical axis. A distance between a focal point of light having a first wavelength and a focal point of light having a second wavelength is about 50 μm or less at a wide-angle position and a telephoto position. The first wavelength corresponds to green light, the second wavelength corresponds to near infrared (NIR) light.

A variable magnification optical system according to the present invention includes a C lens group having positive refractive power, a B lens group having negative refractive power, and an A lens group having positive refractive power in order from an image side and includes an N lens group having negative refractive power on an object side in relation to the A lens group, wherein when zooming from a wide angle end to a telephoto end, at least the A lens group, the B lens group, and the N lens group are moved relative to an image plane and a predetermined conditional expression is satisfied.

A variable magnification optical system according to the present invention includes, in order from an object side: a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a following lens group, wherein at least the second lens group is moved so that a gap between the first lens group and the second lens group increases and a gap between the second lens group and the third lens group decreases when zooming from a wide angle end to a telephoto end, and a predetermined conditional expression is satisfied.

A zoom lens system includes a positive first lens group, a negative second lens group, a positive intermediate lens group, and a negative image-side lens group. Upon zooming from the short to long focal length extremities, a distance between the first and second lens groups increases, and a distance between the second and intermediate lens groups decreases. The image-side lens group consists of two lens elements. The following conditions are satisfied:

−6.0<f1/f2<−4.3,

−5.4<f1/fIMG<−3.9,

and

0.3<D2/fw<3.0.

f1, f2 and fIMG designate the focal lengths of the first, second and the image-side lens groups, respectively. D2 designates a distance between the second lens group and the intermediate lens group, at the short focal length extremity. fw designates the focal length of the zoom lens system at the short focal length extremity.

The present disclosure relates to an optical lens, in particular to a camera optical lens. The camera optical lens includes, from an object side to an image side in sequence: a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, the first lens has a positive refractive power, the second lens has a positive refractive power, and the third lens has a negative refractive power, and the camera optical lens satisfies the following conditions: −20.00≤f2/f3≤−10.00, and 0.50≤d1/d3≤3.00, where f2 denotes a focal length of the second lens, f3 denotes a focal length of the third lens, d1 denotes an on-axis thickness of the first lens, and d3 denotes an on-axis thickness of the second lens. The camera optical lens can obtain high imaging performance and a low TTL.

Provided is a camera optical lens including, sequentially from an object side to an image side, first to seventh lenses. The camera optical lens satisfies following conditions: 20.00≤R7/d7≤30.00; 20.00≤v7−v5≤30.00; and −12.00≤(R1−R2)/(R3−R4)≤−1.00, where v5 denotes an abbe number of the fifth lens; v7 denotes an abbe number of the seventh lens; R1 denotes a curvature radius of an object side surface of the first lens; R2 denotes a curvature radius of an image side surface of the first lens; R3 denotes a curvature radius of an object side surface of the second lens; R4 denotes a curvature radius of an image side surface of the second lens; R7 denotes a curvature radius of an object side surface of the fourth lens; and d7 denotes an on-axis thickness of the fourth lens. The camera optical lens can achieve high optical performance such as large-aperture, wide-angle and ultra-thin.

A zoom optical system includes a plurality of lens units, the plurality of lens units consist of lens units having a positive refractive power and lens units having a negative refractive power, and the lens units having a positive refractive power include a positive lens unit and an image-side positive lens unit, the image-side positive lens unit is not moved, in the lens plurality of units, a space between the lens units disposed adjacently is changed at a time of zooming, at a time of focusing, or at a time of zooming and at a time of focusing, the positive lens unit includes a predetermined positive lens satisfying the following Conditional Expression (2), and the following Conditional Expression (1) is satisfied:

0.1≦fGBUN1/fGPM≦2.1  (1), and

60.8≦νdGPMP1≦100.0  (2).

In an image pickup apparatus including an optical system and an image pickup element, the optical system includes, in order from an object side to an image side, lens(es), an aperture stop, and lens(es). The lens arranged at the most image side in the optical system is a negative lens, and an infrared cut film is formed on at least one lens surface in the optical system. An optical axial distance from the exit pupil of the optical system to the image plane when focusing on an infinite object, an optical axial distance from the lens surface provided with the infrared cut film to the image plane when focusing on the infinite distance object, the curvature radius of the lens surface provided with the infrared cut film, and a radius of a circle circumscribed about an effective imaging area of the image pickup element are appropriately set.

A variable magnification optical system includes, sequentially from an object 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, and a fifth lens unit having a positive refractive power, and each of the lens units makes a different movement relatively to a lens unit that is adjacently positioned at least at one of a time of changing magnification, a time of focusing, and a time of image stabilization.