Abstract: The imaging lens includes a first lens group fixed during focusing and a positive second lens group moving to an object side during focusing from a long-distance object to a short-distance object, in order from a side closest to the object. The field curvature is adjusted by moving the first lens group or a sub-lens group within the first lens group including a lens closest to the object side, as an adjustment group. A stop fixed during the adjustment of the field curvature is disposed closer to an image side than the adjustment group. Conditional expressions relating to the focal length of the whole system, the focal length of the adjustment group, and the height of a paraxial on-axis light ray in the adjustment group are satisfied.

Abstract: An imaging lens is constituted by, in order from the object side to the image side: a first lens group; a stop; and a second lens group having a positive refractive power. The first lens group is constituted by, in order from the object side to the image side: a 1-1 negative meniscus lens having a concave surface toward the image side; a 1-2 negative meniscus lens having a concave surface toward the image side; a 1-3 biconcave lens; and a 1-4 positive lens. The second lens group is constituted by, in order from the object side to the image side: a 2A lens group having a positive refractive power; and a 2B lens group having a positive refractive power as a whole, constituted by a 2B-1 positive lens, a 2B-2 negative lens, and a 2B-3 positive lens. Predetermined conditional formulae are satisfied.

Abstract: A zoom lens is constituted essentially by six lens groups, in order from the object side to the image 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 positive refractive power; a fifth lens group having a negative refractive power; and a sixth lens group having a positive refractive power. The distances between all pairs of adjacent lens groups change when changing magnification from the wide angle end to the telephoto end, and Conditional Formula (1) below is satisfied: ?5<f1/f2<?1.5??(1) wherein f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group.

Abstract: An imaging lens consists of, in order from the object side, a first lens group fixed during focusing, and a positive second lens group moved toward the object side during focusing from a distant object to a close object. The second lens group consists of, in order from the object side, a first cemented lens consisting of a biconvex lens and a negative lens having a smaller absolute value of curvature radius of the object-side surface than that of the image-side surface, and a second cemented lens as a whole having a positive refractive power and consisting of a negative lens having a smaller absolute value of curvature radius of the image-side surface than that of the object-side surface and a positive lens having a smaller absolute value of curvature radius of the object-side surface than that of the image-side surface. The imaging lens satisfies specific condition expressions.

Abstract: The imaging lens includes a first lens group fixed during focusing and a positive second lens group moving to an object side during focusing from a long-distance object to a short-distance object, in order from a side closest to the object. The field curvature is adjusted by moving the first lens group or a sub-lens group within the first lens group including a lens closest to the object side, as an adjustment group. A stop fixed during the adjustment of the field curvature is disposed closer to an image side than the adjustment group. Conditional expressions relating to the focal length of the whole system, the focal length of the adjustment group, and the height of a paraxial on-axis light ray in the adjustment group are satisfied.

Abstract: The imaging lens consists of a first lens group G1, an aperture stop St, and a positive second lens group G2, in order from an object side. The first lens group G1 consists of a 1-1st negative meniscus lens L11 with its convex surface toward the object side, a 1-2nd negative lens L12 with its concave surface toward an image side, a 1-3rd positive lens L13 having a biconvex shape, a 1-4th negative meniscus lens L14 with its convex surface toward the object side, and a 1-5th positive lens L15 with its convex surface toward the object side, in order from the object side. Predetermined conditional expressions are satisfied which relate to a focal length of the whole system, a focal length of the first lens group G1, and a distance on an optical axis between the 1-4th negative meniscus lens L14 and the 1-5th positive lens L15.

Abstract: Provided are an imaging lens, which has a small F number and in which various aberrations are satisfactorily corrected, and an imaging apparatus including the imaging lens. The imaging lens includes, in order from an object side: a first lens that has a biconcave shape; a second lens that is convex toward an image side and has a positive refractive power; a third lens that has a biconvex shape; a fourth lens that has a negative refractive power; a fifth lens that has a positive refractive power; and a sixth lens that has a negative refractive power. Assuming that L1f and L1r are paraxial radii of curvature of an object side surface and an image side surface of the first lens, Conditional Expression (1) is satisfied. 0.1<(L1f+L1r)/(L1f?L1r)<0.

Abstract: A variable magnification optical system includes, in order from the object side: a positive first lens group, which is fixed when changing magnification; a negative second lens group that moves from the object side to the image side when changing magnification from the wide angle end to the telephoto end; and a rearward lens group having a positive refractive power throughout the entire variable magnification range that includes at least one lens group that moves when changing magnification. The first lens group includes, in order from the object side, a positive first lens group front group, a positive first lens group middle group, and a first lens group rear group constituted by a negative lens. The first lens group front group and first lens group middle group include cemented lenses formed by cementing a negative lens and a positive lens, provided in this order from the object side, together.

Abstract: An imaging lens includes, in order from the object side, a first lens group fixed during focusing, a positive second lens group moved toward the object side during focusing from a distant to a close object, and a third lens group fixed during focusing and including one positive lens. The second group includes, in order from the object side, a first cemented lens including a biconvex lens and a negative lens having a smaller absolute value of curvature radius of the object-side surface than of the image-side surface, and a second cemented lens having a positive refractive power and including a negative lens having a smaller absolute value of curvature radius of the image-side surface than of the object-side surface and a positive lens having a smaller absolute value of curvature radius of the object-side surface than of the image-side surface. The imaging lens satisfies specific condition expressions.

Abstract: A zoom lens consists of 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 fifth lens group having positive refractive power in this order from an object side. The third lens group consists of a 3-1st lens group having positive refractive power and a 3-2nd lens group having negative refractive power in this order from the object side. A hand shake blur is corrected by moving the 3-2nd lens group in a direction perpendicular to optical axis. Magnification is changed by changing distances between the lens groups while the fifth lens group is fixed.

Abstract: A variable magnification optical system 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. When changing magnification from the wide angle end to the telephoto end, the first and third lens groups are fixed with respect to an image formation plane, the second lens group moves toward the image side, the fourth lens group moves, and the distance between the fourth and fifth lens groups changes. A rearward lens group constituted by the third, fourth, and fifth lens groups has a positive refractive power throughout the variable magnification range. The transverse magnification ratio of the fourth lens group when focused on an object at infinity is negative throughout the variable magnification range.

Abstract: An imaging lens consists of three lenses of, in order from an object side, a first lens having a biconcave shape, and an object-side surface of which is aspherical, a second lens having negative refractive power and a third lens having positive refractive power with a convex surface facing an image side. The absolute value of a curvature radius of an image-side surface of the third lens is less than the absolute value of a curvature radius of an object-side surface of the third lens.

Abstract: Provided are a rear converter lens and an imaging apparatus capable of achieving favorable optical performance and an appropriate back focal length with high magnification. The rear converter lens RCL consists of, in order from the object side, four lens-groups of positive, negative, negative, and positive lens-groups. In order from the object side, a first lens-group RG1 consists of a negative lens RL11 and a positive lens RL12, a second lens-group RG2 consists of a negative lens RL21 and a positive lens RL22, a third lens-group RG3 consists of a negative lens RL31, a positive lens RL32, and a negative lens RL33, and a fourth lens-group RG4 consists of a biconvex lens RL41 and a negative lens RL42. Here, 0.22<cf/f12<1 is satisfied, where f12 is a composite focal length of the first lens-group RG1 and the second lens-group RG2, and cf is a focal length of the rear converter lens RCL.

Abstract: A zoom lens is constituted by, in order from the object side to the image side: a positive first group which is fixed when changing magnification, a negative second lens group which moves when changing magnification, a negative third lens group which moves when changing magnification, and a positive fourth lens group which is fixed when changing magnification. The first lens group is constituted by a 1a lens of a negative meniscus shape, a positive 1b lens, and a positive 1c lens. The second lens group is constituted by a negative 2a lens, a biconcave 2b lens, a positive 2c lens, and a negative 2d lens. The third lens group is constituted by a negative 3a lens and a positive 3b lens. The fourth lens group includes a 4a lens, an aperture stop, and a positive 4b lens, which are consecutively provided from the most object side thereof.

Abstract: The imaging lens consists of, in order from an object side: a first lens group G1; a diaphragm; and a second lens group G2 that has a positive refractive power. The first lens group G1 consists of, in order from the object side, a first A lens group G1A that consists of two negative meniscus lenses concave toward an image side, and a first B lens group G1B that consists of only one positive lens or a negative lens and a positive lens. The second lens group G2 consists of, in order from the object side, a biconvex lens, a biconcave lens, one or two biconvex lenses, and a negative meniscus lens that is concave toward the object side. With such a configuration, the imaging lens satisfies predetermined conditional expressions.

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 three lenses. The second lens group includes four lenses. The third lens group includes six lenses and an aperture stop. The fifth lens group includes a single lens component.

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: The imaging lens includes, in order from the object side, a first lens group that remains stationary during focusing; a diaphragm; and a positive second lens group that moves to the object side during focusing from a long range to a close range. The first lens group includes, in order from the object side: a negative meniscus lens that has an absolute value of a radius of curvature of an image side surface smaller than that of an object side surface, a negative lens, a positive lens, and a negative lens. The second lens group includes five or less lenses, and includes: a positive Z lens that is formed continuously in order from a most image side; a negative Y lens that has an absolute value of a radius of curvature of an object side surface smaller than that of an image side surface; and a positive X lens.

Abstract: The imaging lens includes, in order from the object side, a first lens group that remains stationary during focusing; a diaphragm; and a positive second lens group that moves to the object side during focusing from a long range to a close range. The second lens group includes a positive Z lens that is formed continuously in order from a most image side, a negative Y lens that has an absolute value of a radius of curvature of an object side surface smaller than an absolute value of a radius of curvature of an image side surface, a positive X lens, and a negative W lens that has an absolute value of a radius of curvature of an image side surface smaller than that of an object side surface. The imaging lens satisfies a conditional expression about of the radii of curvature of the X lens and the W lens.

Abstract: An imaging lens is constituted by, in order from the object side to the image side: a first lens group; a stop; and a second lens group having a positive refractive power. The first lens group is constituted by, in order from the object side to the image side: one or two negative meniscus lenses, a biconcave lens, and a biconvex lens. The second lens group is constituted by, in order from the object side to the image side: a 2A lens group having a positive refractive power as a whole, constituted by a positive lens, a negative lens, and a positive lens; and a 2B lens group having a positive refractive power as a whole, constituted by a positive lens, a negative lens, and a positive lens. A predetermined conditional formula is satisfied.