An optical lens includes a first lens, a second lens, a third lens, a fourth lens, a first cemented lens and aperture stop. The first lens is closest to a magnified side of the optical lens, one of the second lens and the third lens is a first aspheric lens, and the fourth lens is a second aspheric lens and disposed between the first cemented lens and a minified side of the optical lens. The optical lens has at most two plastic lenses, and the optical lens satisfies the condition of 3.5<D1/DL<5.5, where D1 denotes a lens diameter of the first lens and DL denotes a lens diameter of the fourth lens.

A zoom lens consisting of, in order from an object side to an image side, a first lens unit having a negative refractive power, and a rear lens unit having one or more lens units and having a positive refractive power as a whole. Intervals between adjacent lens units change during zooming. The first lens unit has at least three meniscus lenses each having a negative refractive power and a convex shape toward the object side. At least one of the at least three meniscus lenses includes an aspherical surface having a positive aspherical amount. A predetermined condition is satisfied.

The present invention discloses a portable zoom microscope, comprising a case (15) and an optical system assembly installed in the case (15), characterized in that the optical system assembly comprises an objective I (1), an objective II (2), an eyepiece III (3), an eyepiece II (4) and an eyepiece I (5) arranged in sequence along an optical axis Z from an object plane to eyes, wherein the objective I (1) is a positive lens, the objective II (2) is a negative lens, the eyepiece III (3) is a positive lens, the eyepiece II (4) is a positive lens, and the eyepiece I (5) is a negative lens, which effectively eliminates the longitudinal chromatic aberration and the lateral colour, so that the zoom microscope can distinguish the details of small objects more clearly and intuitively, greatly improving the image quality of products.

There is provided a lens system composed, in order from an enlargement side, of a first lens group with positive refractive power and a second lens group with positive refractive power, wherein when zooming from a telephoto end to a wide-angle end, a distance between the first lens group and the second lens group decreases and a distance between the second lens group and a conjugate plane on a reduction side increases. The second lens group includes, closest to an enlargement side thereof, a lens with a second end surface that is concave on the enlargement side, and the first lens group includes a lens with an effective diameter of a first end surface closest to the reduction side that is larger than a maximum diameter in the second lens group.

A zoom lens including from object side: a positive first unit; at least one negative unit moving toward image side for zooming from wide to telephoto; and at least two positive units each moving toward object side for the zooming, in which the positive first unit includes a biconcave lens closest to object side, in which an N unit is one of the at least one negative unit and having largest amount of movement during the zooming, and P unit is one of the at least two positive units having largest amount of movement during the zooming; in which focal lengths of the first lens unit, of the zoom lens at wide end and telephoto end, a difference between distances from the N unit to image plane at telephoto end and at wide end and a distance from the P unit to image plane at telephoto end are appropriately set.

A magnification-variable optical system having a small size, a wide angle of view, and high optical performance, an optical apparatus including the magnification-variable optical system, and a method for manufacturing the magnification-variable optical system are provided.

A magnification-variable optical system ZL used for an optical apparatus such as a camera 1 includes a first lens group G1 having a negative refractive power and including at least two lenses, and a rear group GR including at least one lens group disposed on an image side of the first lens group G1, and is configured so that a distance between lens groups adjacent to each other changes at magnification change and a condition expressed by predetermined condition expressions is satisfied.

A zoom lens consisting of, in order from an object side to an image side, a first lens unit having a negative refractive power, and a rear lens unit having one or more lens units and having a positive refractive power as a whole. Intervals between adjacent lens units change during zooming. The first lens unit has at least three meniscus lenses each having a negative refractive power and a convex shape toward the object side. At least one of the at least three meniscus lenses includes an aspherical surface having a positive aspherical amount. A predetermined condition is satisfied.

The embodiment relates to a lens assembly and a camera module including the same.

The lens assembly according to the embodiment may include a housing 20, a first group lens assembly 210 disposed in the housing 20, and a second group lens assembly 320 disposed at one side of the first group lens assembly 210. The first group lens assembly 210 may be a fixed lens assembly, and may include a first lens 211 and a liquid lens 215. The second group lens assembly 320 may be a movable lens assembly and may include a second lens group 220. In an embodiment, the first group lens assembly 210 may have a negative (−) refractive power as a whole, and the second group lens assembly 320 may have a positive (+) refractive power as a whole.

A zoom lens includes a first lens group with a negative refractive power, a second lens group with a positive refractive power, and an aperture stop disposed in and movable with the second lens group. Each of the first lens group and the second lens group moves individually. The zoom lens further includes a doublet lens disposed on a first side of the aperture stop and between the first lens group and the aperture stop, and at most two lenses including at least one aspheric lens are disposed on a second side of the aperture stop.

An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions,

νdLZ<35.0, and

0.702<θgFLZ+(0.00316×νdLZ), where νdLZ: Abbe number of the lens with reference to d-line, and θgFLZ: a partial dispersion ratio of the lens, wherein θgFLZ is defined by the following expression,

θgFLZ=(ngLZ−nFLZ)/(nFLZ−nCLZ). wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.