Abstract: Large aperture compact lens and a camera design using the lens are described. The lens comprises from object to image, three lens groups with a first lens group having a negative or positive power and comprising 3-4 lens elements, a second lens group having positive power and 3-4 elements including an aperture stop, at least one cemented doublet and one positive power lens made from athermic optical material, and a third lens group comprising 1-3 elements.

Abstract: An optical system includes a first lens unit that has a positive refractive power; a second lens unit that is arranged to move during focusing and has a positive or negative refractive power; and a third lens unit that has a positive or negative refractive power. The first lens unit, the second lens unit, and the third lens unit are disposed in that order from an object side to an image side. During the focusing, an interval between adjacent lens units changes. In the optical system, a focal length f of the entire optical system, a distance LD along an optical axis from a lens surface of the first lens unit that is closest to the object side to an image plane, a material of positive lenses included in the first lens unit, and an arrangement of the positive lenses included in the first lens unit are appropriately set.

Abstract: An imaging apparatus and a method for producing the same are provided. The imaging apparatus includes a display panel, including a first face and a second face arranged opposite to each other; an imaging device on the second face of the display panel; and an optical assembly in an optical path where ambient lights pass through the first face and the second face in sequence and enter the imaging device, the optical assembly being configured to refract at least part of the ambient lights so that the refracted lights bypass shielding members in the display panel and are incident on the imaging device.

Abstract: An objective optical system for endoscope consists of, in order from an object side, a first negative lens L1 which is planoconcave, and of which a flat surface is directed toward the object side, a second meniscus lens L2 having a convex surface directed toward an image side, a third positive meniscus lens L3 having a convex surface directed toward the object side, a fourth positive lens L4, and a cemented lens in which fifth positive lens L5 and a sixth negative lens L6 are cemented. Focusing is carried out by the third positive meniscus lens moving along an optical axis AX, and the following conditional expressions (1-1) and (1-2) are satisfied: 0.41<|flp/f2<1??(1-1), and 0.55<d45/flp<1??(1-2).

Abstract: Near-to-eye systems and head-mounted displays and more particularly but not exclusively to an optimized freeform wedge-shaped prism design having free-form surfaces efficiently mathematically represented and configured to provide both high resolution and a large exit pupil heretofore unachieved.

Abstract: An imaging lens includes a first lens group and a second lens group, arranged in this order from an object side to an image plane side. The first lens group includes a first lens, a second lens, and a third lens. The second lens group includes a fourth lens, a fifth lens having positive refractive power, a sixth lens having two aspheric surfaces, and a seventh lens having two aspheric surfaces. The imaging lens has a total of seven single lenses. The first to seventh lenses are arranged respectively with a space in between. The third lens is formed in a shape so that a surface on the object side is convex. The fourth lens is formed in a shape so that a surface on the object side is concave. The fifth lens is formed in a shape so that a surface on the image plane side is concave.

Abstract: A zoom lens includes a unit LN, a unit LP and a rear group LR, and the rear group LR has a positive unit LRP on a side closest to an image, where the unit LRP includes a positive lens GRP that has a meniscus shape having a convex surface facing the image side thereof and made of resin material. Focal lengths of the zoom lens at wide-angle end, the unit LRP, and the unit LP, back focus at telephoto end, an amount of movement of the unit LRP when zooming from wide-angle end to telephoto end, thickness on an optical axis of the positive lens GRP, and a distance in optical axis direction between center on a lens surface on object side of the positive lens GRP and an end of an effective surface of the lens surface on the object side are each appropriately set.

Abstract: The zoom lens of the present invention includes a positive lens unit LP (LULP) disposed closest to an object side, a negative lens unit LNF (LULNF) disposed at an image side of LULP, and an aperture stop disposed at image side of LULNF. The zoom lens further includes at image side of aperture stop, successively in order from object side to image side, a positive lens unit LP1, a negative lens unit LN1 (LULN1), a positive lens unit LP2 (LULP2), and a negative lens unit LN2 (LULN2), in which intervals between adjacent lens units are changed during zooming. LULN1 moves during focusing. The focal length and the total length of zoom lens at a telephoto end, the changing amount from interval between LULP2 and LULN2 at a wide angle end to that at telephoto end, and the total length of zoom lens at wide angle end are appropriately set.

Abstract: An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. At least one lens among the first to the sixth lenses has positive refractive power. The seventh lens has negative refractive power, wherein both surfaces thereof can be aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the seventh lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: An optical system includes a plurality of lenses. The distance from the object side lens surface of a lens arranged an the most object side to the image plane is longer than the focal length of the entire system. The material of a positive lens G1p arranged on the most object side among positive lenses included in the optical system, and the arrangement and material of a negative lens Gn located on the most object side among negative lenses arranged an the image side of the positive lens G1p are appropriately set.

Abstract: Provided is a zoom lens, including, in order from an object side, a positive first lens unit, a negative second lens unit, a positive third lens unit, a negative fourth lens unit, and a positive fifth lens unit, in which an interval between each pair of adjacent lens units is changed during zooming, in which the second lens unit moves during focusing, and includes, in order from the object side to the image side, a negative lens, a negative lens, a positive lens, and a negative lens, and in which a focal length of the second lens unit, a thickness of the second lens unit on an optical axis, a refractive index of a material of the positive lens included in the second lens unit, and an average value of refractive indices of materials of the negative lenses included in the second lens unit are each appropriately set.

Abstract: Systems and methods described herein are directed towards controlling a level of detail for geostreaming data. In some examples, an identifying event data that includes location information. A polygon may be defined that comprises points on a map corresponding to the event data. A first level of detail may be determined and a fidelity of the polygon may be changed based at least in part on the first level of detail. Second event data may be received that identifies a location of an object. It may be identified whether the object is within the location information and a user interface may be prepared that presents whether the object is in an affected area.

Abstract: Provided is the image pickup optical system including a first lens unit, a second lens unit, and a third lens unit disposed in an order from an object side to an image side, in which an interval between adjacent lens units is changed during focusing. The third lens unit includes an aperture stop. A distance on an optical axis from a lens surface closest to object side to aperture stop when focused at infinity Lf, a distance on optical axis from aperture stop to a lens surface closest to image side when focused at infinity Lr, a distance on optical axis from a lens surface closest to object side to an image plane when focused at infinity L, a focal length of the entire system f, and a moving amount of first lens unit during focusing from infinity to a closest distance M are appropriately set.

Abstract: The present disclosure discloses a camera optical lens. The camera optical lens including, in an order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The camera optical lens further satisfies specific conditions.

Abstract: A lens module includes a first lens, an object-side surface thereof being convex; a second lens, both surfaces thereof being convex; a third lens, both surfaces thereof being concave; a fourth lens having negative refractive power, both surfaces thereof being convex; a fifth lens, an object-side surface thereof being concave; and a sixth lens, an object-side surface thereof being convex. The first to sixth lenses are sequentially disposed in numerical order from the first lens to the sixth lens from an object side of the lens module toward an image side of the lens module.

Abstract: The imaging lens consists of, in order from the object side, a first lens group having a positive power, a second lens group having a negative power, and a third lens group. The first lens group consists of, in order from the object side, a positive front group, a diaphragm, and a positive rear group. The front group has a negative lens and a positive lens, the rear group has a negative lens and a positive lens, the second lens group consists of one negative lens, and the third lens group has a negative lens and a positive lens. During focusing, only the second lens group moves. The following conditional expression relating to a focal length of the second lens group and a focal length of the third lens group is satisfied: 2.5<|f3/f2|.

Abstract: An imaging lens includes first, second, third, fourth, fifth, sixth and seventh lens elements arranged in a sequence from an object side to an image side along an optical axis. Each lens element has an object-side surface and an image-side surface. The object-side of the third lens element has a convex portion in a vicinity of a periphery. The object-side of the fifth lens element has a convex portion in a vicinity of the optical axis and a concave portion in a vicinity of a periphery. The object-side of the sixth lens element has a concave portion in a vicinity of a periphery. All of lens elements having refracting power of the imaging lens are the first, second, third, fourth, fifth, sixth and seventh lens elements.

Abstract: A method of manufacturing a camera module that is low profile and that can achieve superior resolving power, a camera module, and an imaging device are provided. A positioning step of positioning an object-side group optical unit (12a) along an optical axis direction with the use of a jig (40) such that the object-side group optical unit (12a) is located so as not to be in contact with an image-plane-side group lens (32a) and a fixing step of fixing the object-side group optical unit (12a) to a lens holder (20) are included.

Abstract: A system for guidance of an imaging device may include a handheld imaging device, a multidirectional feedback device, and a control unit in communication with the multidirectional feedback device and the handheld imaging device. The control unit may be configured to receive a target location, determine an initial position and pose of the handheld imaging device, calculate a position and pose deviation relative to said initial position and pose, translate said position and pose deviation into control data, and transmit said control data to the multidirectional feedback device, wherein the multidirectional feedback device uses control data to provide an operator with feedback to guide the handheld imaging device towards the target.

Abstract: An inverted equal-magnification relay lens includes, in order from an object side: a first lens group having a positive power, and disposed near an object; a second lens group having a positive power, and disposed at a predetermined distance from the first lens group; and a third lens group having a negative power; wherein an entrance pupil position is more toward an object surface side than the first lens group, an exit pupil position is more toward a third lens group side than an image surface, and the following Formulas (1) and (2) are satisfied: 0.65?|G1F/G2F|?2.0 . . . (1); 0.35?|G3F/G2F|?3.1 . . . (2); where: G1F: a focal length of the first lens group; G2F: a focal length of the second lens group; and G3F: a focal length of the third lens group.

Abstract: The zoom lens includes: a first optical system on a magnification side; and a second optical system on a reduction side in a state where the intermediate image is formed between the magnification side and the reduction side. The first optical system includes, in order from the magnification side, a first-1 lens group which has a positive power, and a first-2 lens group which has a positive power. The second optical system includes, in order from the magnification side, a second-1 lens group which has a positive power, a second-2 lens group which has a positive power, and a second-3 lens group which has a positive power. The first-2 lens group, the second-1 lens group, and the second-2 lens group move during zooming. The first-1 lens group and the second-3 lens group remain stationary during zooming.

Abstract: An optical imaging system is described including first to sixth lenses sequentially disposed from an object side to an image side, and an image sensor configured to convert incident light reflected from a subject, having passed through the first to sixth lenses, into an electrical signal. One of the first to sixth lenses includes a spherical object-side surface and another of the first to sixth lenses includes corresponding aspherical object-side surfaces. The first to sixth lenses include corresponding aspherical image-side surfaces, and a lens of the first to sixth lenses that is closer to the object side than the one of the first to sixth lenses including the spherical object-side surface, has a highest refractive index among the first to sixth lenses.

Abstract: An optical assembly for a point action camera with a wide field of view includes multiple lens elements configured to provide a field of view in excess of 150 degrees. One or more lens elements has an aspheric surface. The optical assembly exhibits a low inward field curvature of less than 75 microns.

Abstract: The present invention relates to a solar position tracking accuracy measurement system based on an optical lens, by which the solar position tracking accuracy of a tracker can be effectively analyzed and detected in real-time by using a technique on the basis of an astronomical analysis on the trajectory of the sun through an accurate measurement based on an optical lens, thereby establishing the reproducibility of a physical measurement method, calculating an error angle according to the vertical incidence of solar light and minimizing physical errors.

Abstract: Provided is a zoom lens, including: a negative first lens unit; an aperture stop; and a positive second lens unit, in which the first and second lens units are configured to move so that an interval between the first and second lens units is changed in an optical axis direction, in which the second lens unit includes a positive lens and a negative lens, and in which, when refractive indices of a material with respect to a wavelengths of 400 nm, 1,050 nm and 1,700 nm are respectively represented by Ns, Nm and Nl, and a relative partial dispersion ? of the material is expressed as: ?=(Ns?Nm)/(Ns?Nl), an average value ?IR(G2p)AVE of relative partial dispersions of materials of the positive lens in the second lens unit, and an average value ?IR(G2n)AVE of relative partial dispersions of materials of the negative lens in the second lens unit are appropriately set.

Abstract: A zoom lens comprising in order from an object side, a first lens unit having a negative refractive power, a second lens unit having a negative refractive power, a lens unit having a positive refractive power, and a rearmost lens unit having a negative refractive power, and the rearmost lens unit is positioned nearest to an image in the plurality of lens units, and at the time of zooming, distances between the lens units in the plurality of lens units change. Moreover, an image pickup apparatus includes the zoom lens, and an image pickup element having an image pickup surface.

Abstract: The present invention discloses a photographic optical system which includes a first lens (focal length f1), a second lens (focal length f2), a third lens (focal length f3), a fourth lens (focal length f4), a fifth lens (focal length f5), a sixth lens (focal length f6) and a seventh lens (focal length f7). The photographic optical system disclosed in the present invention by optimizing rationally face shape, distributing focal power, selecting optical material, is designed as a big relative aperture photographic optical system, and can provide the imaging performance in low illumination environment.

Abstract: An imaging lens for a solid-state imaging sensor includes, in order from an object side to an image side of the imaging lens, a first through sixth lens. The first lens has positive refractive power. The second lens has positive refractive power. The third lens has negative refractive power. The fourth lens has positive or negative refractive power and aspheric surfaces facing the object side and the image side. The fifth lens has positive refractive power. The sixth lens has negative refractive power and aspheric surfaces facing the object side and the image side.

Abstract: An inner focusing lens has sequentially from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a negative refractive power. The first lens group has negative meniscus lenses disposed farthest on the object side thereof. The second lens group is moved along the optical axis whereby focusing from a focus state for an object at infinity to a focus state for the minimum object distance is performed. The inner focusing lens satisfies predetermined conditions and thereby, realizes a compact inner focusing lens having high imaging performance at wide angles, suitable for compact cameras having a function of capturing video.

Abstract: A projection zoom lens is essentially constituted by, in order from the magnification side: a negative first lens group; a positive second lens group; a third lens group; a positive fourth lens group; a fifth lens group; and a positive sixth lens group. The distance between the first and second lens groups is shorter, the distance between the second and third lens groups is longer, the distance between the third and fourth lens groups is shorter, the distance between the fourth and the fifth lens groups is longer, and the distance between the fifth and sixth lens groups is longer at the telephoto end than at the wide angle end. A lens having a negative refractive power in the paraxial region is provided most toward the magnification side in the first lens group. The fifth lens group has a negative lens.

Abstract: An optical imaging lens includes: a first, second, third and fourth lens element, the first lens element has negative refractive power, the second lens element has an image-side surface with a concave part in a vicinity of the optical axis, the third lens element has positive refractive power, and has an object-side surface with a convex part in a vicinity of the optical axis, the fourth lens element has an image-side surface with a concave part in a vicinity of the optical axis, where the optical imaging lens set does not include any lens element with refractive power other than said first, second, third and fourth lens elements.

Abstract: A zoom lens consists of a negative first lens group, a positive second lens group, and a positive third lens group. Upon zooming from the wide angle end to the telephoto end, the first, second, and third lens groups are moved such that distance between the first lens group and the second lens group is reduced, and distance between the second lens group and the third lens group is increased. The first lens group is composed of a negative lens and a positive lens from the object side. The zoom lens satisfies given conditional expressions related to radius of curvature, center thickness, refractive index, and Abbe number of the negative lens and refractive index of the positive lens of the first lens group, and distance from the most object side surface to the most image side surface of the first lens group on the optical axis.

Abstract: An inner focusing lens has sequentially from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a negative refractive power. The first lens group has negative meniscus lenses disposed farthest on the object side thereof. The second lens group is moved along the optical axis whereby focusing from a focus state for an object at infinity to a focus state for the minimum object distance is performed. The inner focusing lens satisfies predetermined conditions and thereby, realizes a compact inner focusing lens having high imaging performance at wide angles, suitable for compact cameras having a function of capturing video.

Abstract: A zoom lens is provided which has a wide angle of view and is bright and in which the entire lens system is compact and which can achieve high optical characteristic over the entire zoom range.

Abstract: The present invention provides a camera device and an optical imaging lens thereof. The optical imaging lens comprises six lens elements positioned in an order from an object side to an image side. Through controlling the convex or concave shape of the surfaces of the lens elements, the view angle of the optical imaging lens is efficiently increased to shows better optical characteristics.

Abstract: A zoom lens including, in order from an object side: a positive first lens unit; a negative second lens unit; and a positive third lens unit, in which: an interval between the first and second lens units is increased, and an interval between the second and third lens units is decreased during zooming from a wide angle end to a telephoto end; the second lens unit is an image stabilizing lens unit which moves with a component of motion in a direction perpendicular to an optical axis whereby an imaging position is moved in the direction of motion perpendicular to the optical axis; and a focal length of an entire system at the wide angle end, a focal length of the first lens unit, and a movement amount of the first lens unit during zooming from the wide angle end to the telephoto end are each set appropriately.

Abstract: A condensing system and method with a plurality of LEDs is disclosed. The LEDs are positioned on the same plane. A first condensing lens is disposed at front of each LED, a second condensing lens is disposed at front of each first condensing lens, a third condensing lens is disposed at front of each second condensing lens, and a fourth condensing lens is disposed at front of all the third condensing lenses. After the light emitted by each LED is condensed by the corresponding first condensing lens, second condensing lens and third condensing lens, the divergence angle of the light becomes smaller, forming a bunch of nearly parallel light beams. The bunches of nearly parallel light beams simultaneously transmit through the fourth condensing lens, and then combine. The condensing system can be used as the light source with imaging lenses disposed therebehind to form an imaging system.

Abstract: A zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, the zoom lens system, in order from an object side to an image side, comprising: a first lens unit having negative optical power and being composed of at least two lens elements; and a second lens unit having positive optical power, wherein in zooming from a wide-angle limit to a telephoto limit at the time of image taking, the lens units are individually moved along an optical axis to vary magnification such that an interval between the first lens unit and the second lens unit decreases, and the conditions: fW/D1>7.5 and Z=fT/fW>4.0 (fW: a focal length of the entire system at a wide-angle limit, fT: a focal length of the entire system at a telephoto limit, D1: a center thickness of a lens element located on the most object side in the first lens unit) are satisfied; an imaging device; and a camera.

Abstract: This super-wide lens substantially consists of a positive first lens group, a positive second lens group, and a negative third lens group, in this order from the object side. The first lens group and the third lens group are fixed and the second lens group moves toward the object side while focusing from an object at infinity to an object at the closest distance. The first lens group substantially consists of a negative first sub lens group, a positive second sub lens group, an aperture stop, and a positive third sub lens group in this order from the object side. Conditional expressions (1) and (2) are satisfied: 0.15<f1/f2<0.60??(1) 2.5<f2/f<7.0??(2), where f1: the focal length of the first lens group, f2: the focal length of the second lens group, and f: the focal length of the entire system when focusing on an object at infinity.

Abstract: A zoom lens includes an imaging lens unit having a positive refractive power and provided nearest to an image-side end, and a focusing lens unit having a positive refractive power and provided on an object side of the imaging lens unit. A distance between the imaging lens unit and the focusing lens unit changes during zooming. The focusing lens unit moves during focusing. The imaging lens unit includes, at a position thereof nearest to an object-side end, a negative meniscus lens component that is concave on the object side thereof.

Abstract: A zoom lens system that includes a first lens group including at least one lens and having a negative refractive power, and a second lens group including at least one lens and having a positive refractive power in an order from an object side to an image side, wherein the zoom lens system is configured to perform zooming by changing a distance between the first lens group and the second lens group and satisfies: 2<|f1/fw|<2.5 and 0.60<|f1/f2|<0.85, wherein f1 indicates a synthetic focal length of the first lens group, fw indicates an overall focal length at a wide angle end, and f2 indicates a synthetic focal length of the second lens group.

Abstract: A zoom lens includes first, second, and third lens units respectively having negative, positive, and negative refractive powers in this order from an object side to an image side. The lens units move during zooming such that the spacing between adjacent lens units changes, the second and third lens units are positioned on the object side at a telephoto end when compared to a wide angle end, and the third lens unit moves during focusing. A lateral magnification of the second lens unit at the wide angle end, a lateral magnification of the second lens unit at the telephoto end, a lateral magnification of the third lens unit at the wide angle end, a lateral magnification of the third lens unit at the telephoto end, a focal length of the first lens unit, and a focal length of the second lens unit are appropriately set.

Abstract: A variable magnification optical system includes a negative first lens group, a stop, and a positive second lens group. The distance in an optical axis direction between the first and the second lens groups is reduced when magnification is changed from the wide angle end to the telephoto end. The stop is fixed with respect to an image plane when magnification is changed, and the first lens group includes a positive lens, a negative lens, a negative lens, and a positive meniscus lens with a convex surface on the object side in order from the object side. The optical system satisfies predetermined conditional expressions with respect to the average Abbe number of the positive lens and the positive meniscus lens of the first lens group at the d-line, and the focal length of the entire system at the wide angle end and the focal length of the negative lens.

Abstract: A zoom lens and a photographing apparatus including the zoom lens that includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power that are sequentially arranged from an object side; during zooming from wide to telephoto, the distance between the first and second lens groups decreases and the distance between the second and third lens groups increases; the first lens group includes a first lens having a negative refractive power and is a double-concave lens and a second lens having a positive refractive power that are sequentially arranged from the object side; and the second lens group includes a third lens having a positive refractive power, being disposed closest to the image side, and is a meniscus lens having a concave surface toward the object side.

Abstract: A zoom lens consists of, in order from an object side to an image side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, and a third lens unit having negative refractive power. The first lens unit and the second lens unit move during zooming to make a distance between the first lens unit and the second lens unit larger at a telephoto end than at a wide-angle end. The third lens unit consists of, in order from the object side to the image side, a first lens subunit having positive refractive power and a second lens subunit having negative refractive power, and the second lens subunit moves toward the image side during focusing from an infinite-distance object to a near-distance object.

Abstract: A zoom lens system comprising: a first lens unit having negative optical power; a second lens unit having positive optical power; and a third lens unit having positive optical power, wherein the first to third lens units are individually moved along an optical axis to vary magnification in zooming, each lens unit includes at least one lens element that satisfies the conditions: nd?1.67, vd<59 and 0.000<PgF+0.002×vd?0.664 (nd, vd and PgF: a refractive index to the d-line, an Abbe number to the d-line and a partial dispersion ratio, of the lens element), and the condition: 0.31<Ir/?(|fG1×fG2|) (Ir=fT×tan(?T), fT and ?T: a focal length of the entire system and a half value of maximum view angle, at a telephoto limit, fG1 and fG2: a focal length of each of the first lens unit and the second lens unit) is satisfied; an imaging device; and a camera are provided.

Abstract: A zoom lens includes a first lens group, a second lens group and a third lens group, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens group is with negative refractive power and includes a first lens, a second lens and a third lens, wherein the first lens is with negative refractive power, the second lens is with positive refractive power and the third lens is with negative refractive power. The second lens group is with positive refractive power. The third lens group is with positive refractive power. The third lens satisfies |R31/R32|?0.39, wherein R31 is a radius of curvature of an object side surface of the third lens and R32 is a radius of curvature of an image side surface of the third lens.

Abstract: A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, a third lens unit having a positive refractive power, and a rear lens group including at least one lens unit, the first lens unit is positioned closer to the object side at a telephoto end than at a wide-angle end, the third lens unit includes at least one positive lens, and a partial dispersion ratio ?gF3P of a material of one positive lens in the third lens unit, Abbe's number ?d3P, focal lengths fW and fT of a total system at the wide-angle end and the telephoto end respectively, a focal length f1 of the first lens unit, and a focal length f3 of the third lens unit are appropriately set.

Abstract: A zoom lens includes, in order from the object side, a negative first lens group, a positive second lens group and a positive third lens group, wherein, during magnification change from the wide-angle end to the telephoto end, at least the first and second lens groups are moved such that the interval between the first and second lens groups decreases and the interval between the second and third lens groups increases. The first lens group includes a negative meniscus first-group first lens with a convex object-side surface, a negative meniscus first-group second lens with a convex object-side surface, and a positive first-group third lens with a convex object-side surface, and the second lens group includes a positive lens, a cemented lens formed by a positive lens and a negative lens, a positive lens and a negative lens, in order from the object side. The zoom lens satisfies given conditional expressions.

Abstract: Various embodiments provide an optical system including a first lens group having a plurality of lenses; a second lens group having a plurality of lenses, the second lens group being disposed adjacent the first lens group; a third lens group having a plurality of lenses, the third lens group being disposed adjacent the second lens group; and a detector disposed behind the third lens group. A pupil of the optical system is located external to the first lens group, the second lens group and the third lens group. The second lens group is movable respective to the first lens group and the third lens group so as to convert a configuration of the optical system between a narrow field of view (NFOV) configuration and a wide field of view (WFOV) configuration.