Abstract: An optical system and an optical apparatus that have a wide angle of view and favorable optical performance and a method for manufacturing the optical system are provided. An optical system OL used for an optical apparatus such as a camera 1 includes, sequentially from an object side, a first lens group G1, an aperture stop S, and a second lens group G2, first lens group G1 includes, sequentially from the object side, at least two negative lenses (for example, negative lenses L1n1 and L1n2), a positive lens (for example, a positive lens L1p1), and a back-side negative lens (for example, a negative lens L1nr), and the optical system OL satisfies a condition expressed by a predetermined conditional expression.

Abstract: Provided is a zoom lens having, in order from an object, a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, and a fourth lens group (G4) having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group changes, a distance between the second lens group and the third lens group changes, a distance between the third lens group and the fourth lens group changes, and at least the first lens group (G1) moves. The first lens group (G1) is constituted by a set of cemented lenses, the third lens group (G3) is constituted by, in order from the object, a positive lens and a negative lens, and the conditional expression 0.50<TL/ft<1.

Abstract: Provided is a zoom lens having, in order from an object, a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, and a fourth lens group (G4) having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group changes, a distance between the second lens group and the third lens group changes, a distance between the third lens group and the fourth lens group changes, and at least the first lens group (G1) moves. The first lens group (G1) is constituted by a set of cemented lenses, the third lens group (G3) is constituted by, in order from the object, a positive lens and a negative lens, and the conditional expression 0.50<TL/ft<1.

Abstract: Provided is a zoom lens having, in order from an object, a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, and a fourth lens group (G4) having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group changes, a distance between the second lens group and the third lens group changes, a distance between the third lens group and the fourth lens group changes, and at least the first lens group (G1) moves. The first lens group (G1) is constituted by a set of cemented lenses, the third lens group (G3) is constituted by, in order from the object, a positive lens and a negative lens, and the conditional expression 0.50<TL/ft<1.

Abstract: A zoom lens ZL comprising a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power, wherein the first lens group G1 includes a first lens having negative refractive power and a second lens which is a plastic lens having positive refractive power, the second lens group G2 includes a third lens having positive refractive power, a fourth lens having positive refractive power and a fifth lens having negative refractive power, the third lens group G3 includes a sixth lens having positive refractive power, and the conditional expressions: 1.50<(?f1)/fw<2.52, 0.4<(?f1)/fL2 <0.8, n2×n2×?2<77.0 are satisfied respectively.

Abstract: A zoom lens ZL comprising a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power, wherein the first lens group G1 includes a first lens having negative refractive power and a second lens which is a plastic lens having positive refractive power, the second lens group G2 includes a third lens having positive refractive power, a fourth lens having positive refractive power and a fifth lens having negative refractive power, the third lens group G3 includes a sixth lens having positive refractive power, and the conditional expressions: 1.50<(?f1)/fw<2.52, 0.4<(?f1)/fL2<0.8, n2×n2×?2<77.0 are satisfied respectively.

Abstract: A wide-angle lens WL including, in order from an object: a first lens L1 which is a negative meniscus lens having a convex surface facing the object; a second lens L2 which is a positive lens; a third lens L3 which is a negative lens; a fourth lens L4 which is a positive lens; and a fifth lens L5 which is a positive lens, wherein the condition of 0.2<d8/f<0.64 is satisfied, where d8 denotes an air distance between the fourth lens L4 and the fifth lens L5, on an optical axis, upon focusing on an object point at infinity, and f denotes a focal length of the wide-angle lens WL upon focusing on an object point at infinity.

Abstract: A wide-angle lens WL including, in order from an object: a first lens L1 which is a negative meniscus lens having a convex surface facing the object; a second lens L2 which is a positive lens; a third lens L3 which is a negative lens; a fourth lens L4 which is a positive lens; and a fifth lens L5 which is a positive lens, wherein the condition of 0.2<d8/f<0.64 is satisfied, where d8 denotes an air distance between the fourth lens L4 and the fifth lens L5, on an optical axis, upon focusing on an object point at infinity, and f denotes a focal length of the wide-angle lens WL upon focusing on an object point at infinity.