Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ?dLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where ?dLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ=(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.

Abstract: [Problem to be Solved] There are provided an optical system having good imaging performance, an optical apparatus, and a method for manufacturing the optical system. [Solution] An optical system OL used in an optical apparatus, such as a camera 1, includes a diffractive optical element GD and at least one specific lens Lp, which is a lens made of crystalline glass. The specific lens Lp satisfies the condition expressed by the following expression: ?gFp+0.0017×?dp<0.730, where ?gFp represents partial dispersion ratio of a medium of the specific lens Lp, and ?dp represents the Abbe number of the medium of the specific lens Lp at a d line.

Abstract: An optical system (LS) Includes lenses (L22,L23) satisfying the following conditional expressions, ?dLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where ?dLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ?(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.

Abstract: There are provided an excellent diffractive optical element having a small amount of flare coloring and unaffected optical performance with a decrease in diffraction efficiency minimized and an optical system and an optical apparatus using the diffractive optical element. A diffractive optical element GD used in an optical system OL of a camera 1, which is an optical apparatus, and including a diffraction grating so that the diffractive optical element GD serves as a lens is so configured that the grating height h0 of the diffraction grating in a central region Ac around an optical axis Z is smaller than the grating height hmax of the diffraction grating in a peripheral region Ap.

Abstract: This variable power optical system (ZL(1)) has a plurality of lens groups (G1-G7), and the intervals between the respectively adjacent lens groups change during power variation. The plurality of lens groups include a first focusing lens group (G6) that moves during focusing, and a second focusing lens group (G7) that is disposed closer to the image surface than is the first focusing lens group and moves so as to follow a track different from that of the first focusing lens group. The first focusing lens group (G6) and the second focusing lens group (G7) each have a negative refractive power and satisfy conditional expression: 0.40<MTF1/MTF2<1.

Abstract: This zoom optical system (ZL(1)) has a plurality of lens groups (G1-G7), wherein when during zooming, distances between adjacent lens groups vary. The plurality of lens groups include: a first focused lens group (G6) that moves during focusing; and a second focused lens group (G7) that is disposed closer to an image plane side than the first focused lens group and moves during focusing along a trajectory that is different from that of the first focused lens group. The first focused lens group (G6) and the second focused lens group (G7) both have a negative refractive power and satisfy the following conditional expression, 0.40<fF1/fF2<6.00, where fF1: focal length of first focused lens group and fF2: focal length of second focused lens group.

Abstract: An optical system (OL) used for an optical apparatus such as a camera (1) includes a focusing group (Gf) that moves upon focusing, a diffractive optical element (GD) disposed on an object side of the focusing group (Gf) and a negative lens element (L1n) disposed on the object side of the diffractive optical element (GD). The optical system (OL) satisfies the following expressions 0.030<f/fpf<0.050 nd1n+0.006×?d1n<1.910 35<?d1n where, f: focal length of whole system in infinity focusing state fpf: focal length of diffractive optical element (GD) nd1n: refractive index of medium of negative lens element (L1n) on d-line ?d1n: Abbe number of medium of negative lens element (L1n) on d-line.

Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ndLZ+(0.01425×?dLZ)<2.12, and 0.702<?gFLZ+(0.00316×?dL=), where ndL: a refractive index of the lens with reference to d-line, ?dLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ=(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.

Abstract: An optical system (LS) Includes lenses (L22,L23) satisfying the following conditional expressions, vdLZ<35.0, and 0.702<?gFLZ+(0.00316×?dLZ), where vdLZ: Abbe number of the lens with reference to d-line, and ?gFLZ: a partial dispersion ratio of the lens, wherein ?gFLZ is defined by the following expression, ?gFLZ?(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.

Abstract: An optical system (OL) used for an optical apparatus such as a camera (1) includes a focusing group (Gf) that moves upon focusing, a diffractive optical element (GD) disposed on an object side of the focusing group (Gf) and a negative lens element (Lin) disposed on the object side of the diffractive optical element (GD). The optical system (OL) satisfies the following expressions. 0.030<f/fpf<0.050 nd1n+0.006×?d1n<1.

Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ndLZ+(0.01425×?dLZ)<2.12, and ?dLZ<35.0, where ndLZ: a refractive index of the lens with reference to d-line, and ?dLZ: Abbe number of the lens with reference to d-line.

Abstract: There are provided an excellent diffractive optical element having a small amount of flare coloring and unaffected optical performance with a decrease in diffraction efficiency minimized and an optical system and an optical apparatus using the diffractive optical element. A diffractive optical element GD used in an optical system OL of a camera 1, which is an optical apparatus, and including a diffraction grating so that the diffractive optical element GD serves as a lens is so configured that the grating height h0 of the diffraction grating in a central region Ac around an optical axis Z is smaller than the grating height hmax of the diffraction grating in a peripheral region Ap.

Abstract: [Problem to be Solved] There are provided an optical system having good imaging performance, an optical apparatus, and a method for manufacturing the optical system. [Solution] An optical system OL used in an optical apparatus, such as a camera 1, includes a diffractive optical element GD and at least one specific lens Lp, which is a lens made of crystalline glass. The specific lens Lp satisfies the condition expressed by the following expression: ?gFp+0.0017×?dp<0.730, where ?gFp represents partial dispersion ratio of a medium of the specific lens Lp, and ?dp represents the Abbe number of the medium of the specific lens Lp at a d line.