A variable magnification optical system comprises: a first lens group having a negative refractive power; at least one positive lens disposed closer to an image side than the first lens group; an aperture, the at least one positive lens being disposed between the first lens group and the aperture; an intermediate group having a plurality of lenses disposed closer to the image side than the aperture; and a vibration-reduction lens group disposed closer to the image side than the intermediate group. The plurality of lenses of the intermediate group integrally move upon varying magnification, and the system satisfies the conditional expression 1.500<f(1˜Gn)t/ft<100.000, where f(1˜Gn)t denotes a composite focal length from the first lens group to the intermediate group in a telephoto end state, and ft denotes a focal length of the entire system in the telephoto end state.

A six-piece optical image capturing system is disclosed. In order from an object side to an image side, the optical lenses along the optical axis include a first lens with refractive power; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power; a fifth lens with refractive power, and a sixth lens with negative refractive power. At least one lens among the first lens to the fifth lens has positive refractive power. The image-side surface and object-side surface of the sixth lens are aspheric, and at least one of the image-side surface and the object-side surface of the sixth lens has an inflection point. The optical lens of the optical image capturing system can increase aperture value and improve the imagining quality for use in compact cameras.

A projection optical system that projects, while enlarging, an image displayed on an image display surface includes in order from an enlargement side: a first negative refractive power lens group; a second negative refractive power lens group; at least one positive or negative refractive power lens group; a stop; and a first positive refractive power lens group. The projection optical system causes magnification variation by varying distances between lens groups. The at least one positive or negative refractive power lens groups disposed between the second negative refractive power lens group and the stop is movable during the magnification variation. The first positive refractive power lens group is an only lens group that is positioned closer to a reduction side than the stop and is also movable during the magnification variation.

A zoom lens includes, 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 three or more lens units. A distance between adjacent lens units varies during zooming. A predetermined condition is satisfied.

Provided is a camera optical lens including, sequentially from an object side to an image side: a first lens having a negative refractive power; a second lens; a third lens having a positive refractive power; a fourth lens having a negative refractive power; a fifth lens; a sixth lens having a positive refractive power; and a seventh lens having a negative refractive power. At least one of the first to seventh lenses comprises a free-form surface. The camera optical lens satisfies following conditions: −5.00≤f1/f≤−1.00; and 1.50≤d1/d2≤7.00. The camera optical lens can achieve high optical performance while satisfying design requirements for ultra-thin, wide-angle lenses.

A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and two or more additional lens units. In zooming, the first lens unit moves, and an interval between adjacent lens units changes. The refractive index of a negative lens A disposed on a most object side of negative lenses included in the first lens unit is higher than or equal to 1.89, and the negative lens A and a lens B disposed adjacent to an image side of the negative lens A satisfy a predetermined relationship.

An image forming optical system consists of a first optical system and a second optical system in order from a magnification side. An intermediate image is formed between the first optical system and the second optical system. Among the aspherical lenses included in the first optical system, a specific lens, which is the aspherical lens closest to the intermediate image on the optical path, has a meniscus shape of which a surface is convex toward the reduction side in a paraxial region. The image forming optical system satisfies a maximum image height, a focal length, and predetermined conditional expressions for the specific lens.

A camera lens assembly, sequentially from an object side to an image side along an optical axis, includes: a first lens having a negative refractive power; a second lens having a positive refractive power, an object-side surface thereof is a convex surface, and an image-side surface thereof is a concave surface; a third lens having a positive refractive power, and an object-side surface thereof is a convex surface; a fourth lens having a negative refractive power, and an image-side surface thereof is a concave surface; a fifth lens having a positive refractive power; and a sixth lens having a negative refractive power, and at least one of an object-side surface and an image-side surface thereof has an inflection point. Half of a maximal field-of-view HFOV of the camera lens assembly satisfies: HFOV≥55°.

A variable-power optical system (ZL) comprises a first lens group (G1) having a negative refractive power and a succeeding lens group (GR), which are disposed on an optical axis in that order from the object side. When varying magnification from wide angle to telephoto, the space between the adjacent lens groups changes. The succeeding lens group (GR) comprises: a first focusing lens group (G3) having a positive refractive power; and a second focusing lens group (G5) having a positive refractive power. When focusing from infinity to a proximate distance, the first focusing lens group (G3) moves toward the object side, and the second focusing lens group (G5) moves toward the image side.

A projection system has a zooming function and is configured that light rays from a telecentric system enter. The projection system is formed of seven lens groups. The first and seventh lens groups are fixed when the projection magnification is changed, and the second, third, fourth, fifth, and the sixth lens groups move along the optical axis when the projection magnification is changed. The second lens group is formed of one positive lens. The third lens group is formed of one positive lens. The fourth lens group is formed of one or two positive lenses and one negative lens having the center of curvature located at the magnifying side. The fifth lens group is formed of one negative lens having a magnifying-side aspheric surface and a demagnifying-side aspheric surface with each of the surfaces having the center of curvature located at the demagnifying side.