Abstract: A zoom lens is constituted by, in order from the object side: a positive first lens group; a negative second lens group; a positive third lens group; a negative fourth lens group; and a positive fifth lens group. The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle end to the telephoto end. The first lens group is constituted by three lenses, which are negative, positive, and positive in order from the object side. The second lens group is constituted by five lenses, which are negative, negative, positive, positive, and negative in order from the object side. The fifth lens group is constituted by a single lens component.

Abstract: A zoom lens includes, in order from the object side: a positive first lens group; a negative second lens group; a positive third lens group; a negative fourth lens group; and a positive fifth lens group. The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle to the telephoto end. The first lens group includes, in order from the object side, a negative lens, a positive lens, and a positive lens. The fourth lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens, and moves toward the image side when focusing from a far distance to a close distance.

Abstract: An imaging lens with five lenses arranged as, in order from the object side, a first lens with a positive refractive power and a meniscus shape with a convex surface directed toward the object side, a second lens with a biconcave shape, a third lens with a negative refractive power and a meniscus shape with a convex surface toward the image side, a fourth lens with a positive refractive power, and a fifth lens with a negative refractive power, where an image-side surface of the fifth lens includes a concave surface and at least one inflection point, and a predetermined conditional expression is satisfied that achieves a high imaging performance from a central angle of view to a peripheral angle of view, while achieving reduction of an entire length of the lens.

Abstract: An imaging lens substantially consists of five lenses consisting of, in order from the object side: a first lens having a positive refractive power and having a meniscus shape with the convex surface toward the object side; a second lens having a biconcave shape; a third lens having a positive refractive power and having a meniscus shape with the convex surface toward the image side; a fourth lens having a positive refractive power and having a convex surface toward the image side; and a fifth lens having a negative refractive power, wherein a predetermined conditional expression is satisfied.

Abstract: In a zoom lens in which a first lens group having a negative refractive power and a second lens group having a positive refractive power are disposed in order from the object side and zooming is performed by moving the first and the second lens groups, the first lens group is formed of a first lens having a negative refractive power, a second lens, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. Then, when the focal length of the second lens, the focal length of the entire system at the wide angle end, the focal length of the first lens group, and the focal length of the second lens group are taken as fG12, fw, f1, and f2 respectively, the zoom lens is configured to satisfy conditional expressions give below: 0.00<fw/f2<0.50??(1-1); and ?0.19<f1/fG12<0.16??(2-1).

Abstract: An imaging lens substantially consists of, in order from an object side, five lenses of a first lens that has a positive refractive power and has a meniscus shape which is concave toward an image side, a second lens that has a negative refractive power and has a meniscus shape which is concave toward the image side, a third lens that has a negative refractive power and is concave toward the object side, a fourth lens that has a positive refractive power and has a meniscus shape which is convex toward the image side, and a fifth lens that has a biconcave shape and has an aspheric shape which has at least one extreme point on an image side surface. Further, the imaging lens satisfies predetermined conditional expressions.

Abstract: An imaging lens is substantially constituted by six lenses, including: a negative first lens having a concave surface toward the object side; a positive second lens; a negative third lens; a positive fourth lens of a meniscus shape with a concave surface toward the object side; a fifth lens; and a sixth lens having a concave surface toward the image side, the surface toward the image side thereof being an aspherical shape having at least one inflection point thereon, provided in this order from the object side. The imaging lens satisfies a predetermined conditional formula.

Abstract: A zoom lens consists of, in order from the object side, 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 negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a positive refractive power, wherein magnification change is effected by changing all distances between adjacent lens groups. The second lens group is moved from the object side toward the image side during magnification change from the wide-angle end to the telephoto end. The position of the third lens group at the telephoto end is nearer to the image side than the position of the third lens group at the wide-angle end.

Abstract: A zoom lens consists of, in order from the object side, 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 negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a positive refractive power, wherein magnification change is effected by changing all distances between adjacent lens groups. The first lens group is fixed relative to the image plane during magnification change, and the second lens group is moved from the object side toward the image side during magnification change from the wide-angle end to the telephoto end. The sixth lens group includes a positive lens and a negative lens.

Abstract: An imaging lens is constituted essentially by, in order from the object side to the image side, a negative first lens group, a positive second lens group, a stop, and a positive third lens group. The first lens group is constituted essentially by four or fewer lenses, has a positive lens and a negative meniscus lens provided adjacent to each other in this order from the most object side, and further has a negative lens at the most image side. The second lens group is constituted essentially by one single lens. The third lens group is constituted essentially by five or fewer lenses, and has four lenses having refractive powers of different signs adjacent to each other provided in order as lenses most toward the image side. Predetermined conditional formulae are satisfied.

Abstract: An imaging lens consists of, disposed in order from the object side, a front group, a stop, and a rear group, wherein the front group includes, in order from the most-object side, a positive first lens, a negative second lens, and a negative third lens which are adjacently disposed, the rear group consists of two sets of cemented lenses having positive refractive powers and a positive single lens, the object-side cemented lens is formed by cementing, in order form the object side, a positive lens with a convex surface toward the image side and a negative meniscus lens together, the image-side cemented lens is formed by cementing, in order from the object side, a negative meniscus lens with a concave surface toward the image side and a positive lens together, and the image-side cemented lens is disposed at the most-image side of the rear group.

Abstract: An imaging lens consists of, in order from the object side, a front group, a stop, and a rear group, wherein the front group includes, in order from the most-object side, a positive first lens, a negative second lens, a negative third lens which are adjacently disposed, and further includes a final lens of the front group adjacent to the stop, with the surface toward the stop being convex toward the image side, the rear group includes, in order from the image side, two sets of cemented lenses having positive refractive powers, which are adjacently disposed, the object-side cemented lens of the two sets of cemented lenses is formed by cementing a positive lens and a negative meniscus lens together, and the image-side cemented lens is formed by cementing a negative meniscus lens and a positive lens together.

Abstract: An optical system consists essentially of, in order from the magnification side, a first lens having a positive refractive power with a convex surface on the magnification side, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, a fifth lens having a positive refractive power, and a sixth lens having a positive refractive power, wherein the following conditional expressions (1) and (2) are satisfied: 0.17<D2/f<0.80??(1) ?60<?d1??d2<?15??(2) where D2: distance on the optical axis between the first lens and the second lens f: focal length of the entire system ?d1: Abbe number of the first lens with reference to d-line ?d2: Abbe number of the second lens with reference to d-line.

Abstract: An imaging lens, substantially consisting of five lenses, composed of a positive first lens with a convex surface on the object side, a negative second lens with a concave surface on the object side, a third lens having a negative meniscus shape with a convex surface on the object side, a fourth lens having a positive meniscus shape with a concave surface on the object side, and a negative fifth lens with a concave surface on the image side, the image side surface having an aspherical shape with at least one inflection point located inward in a radial direction from the intersection between the image side surface and a principal ray of the maximum angle of view toward the optical axis, disposed in order from the object side, and satisfies given conditional expressions.

Abstract: An imaging lens substantially consists of, in order from an object side, five lenses of a first lens that has a positive refractive power and has a meniscus shape which is convex toward the object side, a second lens that has a negative refractive power, a third lens that has a negative refractive power, a fourth lens that has a positive refractive power, and a fifth lens that has a negative refractive power and has an aspheric shape of which an image side surface has an extreme point. Further, the imaging lens satisfies a predetermined conditional expression.

Abstract: A zoom-lens consists of a positive-first-lens-group, fixed during magnification-change, a negative-second-lens-group, which moves from object-side toward image-side during magnification change from wide-angle-end to telephoto-end, a negative-third-lens-group, which corrects movement of an image-plane during magnification-change, and a positive-fourth-lens-group, which is fixed during magnification-change and includes a stop, in this order from object-side. The first-lens-group consists of a negative-1a-th-lens-group, fixed during focusing, a positive-1b-th-lens-group, which moves during focusing, and a positive-1c-th-lens-group, fixed during focusing, in this order from object-side. The second-lens-group consists of a negative-2a-th-lens-group and a positive-2b-th-lens-group, and a distance therebetween is changed during magnification-change.

Abstract: An imaging lens substantially includes six lenses, constituted by: a first lens having a negative refractive power; a second lens having a positive refractive power; a third lens having a positive refractive power; a fourth lens having a negative refractive power; a fifth lens having a positive refractive power; and a sixth lens having a negative refractive power, a concave surface toward an image side, and at least one inflection point in the surface toward the image side; provided in this order from an object side. The imaging lens satisfies a predetermined conditional formula.

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 imaging lens substantially consists of, in order from an object side, five lenses of a first lens that has a positive refractive power and has a meniscus shape which is convex toward the object side, a second lens that has a biconcave shape, a third lens that has a meniscus shape which is convex toward an image side, a fourth lens that has a positive refractive power, and a fifth lens that has a negative refractive power and has at least one inflection point on an image side surface. Further, the imaging lens satisfies a predetermined conditional expression.

Abstract: A wide angle lens consists of a first lens group having negative refractive power as a whole, a second lens group having positive refractive power as a whole, and a third lens group having positive refractive power as a whole in this order from an object side. The first lens group consists of a positive meniscus lens with its convex surface facing the object side and three negative meniscus lenses, each with its convex surface facing the object side, in this order from the object side. The second lens group includes at least two cemented lenses. The third lens group consists of a 3a-th lens group consisting of a positive meniscus lens with its convex surface facing the object side and a 3b-th lens group that includes at least two cemented lenses and has positive refractive power as a whole, in this order from the object side.