Nikon Corporation

Saburo Masugi

Atsushi Suzuki

Tomoyuki Sashima

Kenji Ishida

Takamichi Kurashige

An optical system comprises a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, arranged in order from an object side. When focusing, the second lens group moves along an optical axis. The optical system satisfies the following conditional expression0.30<{1−(β2)}×(β3)<2.00

Optical system, optical apparatus, and method of manufacturing optical system

An optical system comprises a first lens group having positive refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, arranged in order from an object side, wherein, when focusing, the second lens group moves along an optical axis, and the optical system satisfies the conditional expressions 0.100<BFa/f<0.500 and −5.000<(−G1R1)/f<500.000, where BFa is an air equivalent distance on the optical axis between a lens surface on an image side of a lens disposed closest to an image and the image, f is a focal length of the optical system, and G1R1 is a radius of curvature of a lens surface on the object side for a lens component disposed farthest on the object side in the first lens group.

A zoom lens, comprises: in order from an object, a first lens group (G) having positive refractive power; a second lens group (G) having negative refractive power; a third lens group (G) having positive refractive power; a fourth lens group (G) having negative refractive power; and a fifth lens group (G) having positive refractive power, wherein, upon zooming from a wide-angle end state to a telephoto end state, a distance between each of lens groups and a lens group adjacent thereto changes to satisfy the following conditional expression:2.90<|MV5/MV2|<11.50

Zoom lens, optical apparatus and method for manufacturing the zoom lens

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, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power are arranged in order from an object, and zooming is performed by changing distances between each lens group, and the first lens group (G1) is composed of three or more lenses, the fourth lens group (G4) is composed of two or less lenses, and the fifth lens group (G5) is composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and the following conditional expression (1) is satisfied.8.40<1/(−2)  (1)

A zoom lens (ZL) comprises, in order from an object: a first lens group (G) having negative refractive power; an aperture stop (S); a second lens group (G) having positive refractive power; a third lens group (G) having negative refractive power; and a fourth lens group (G) having positive refractive power. In this zoom lens (ZL), upon zooming from a wide angle end state to a telephoto end state, a distance between the aperture stop (S) and the first lens group (G), a distance between the aperture stop (S) and the second lens group (G), and a distance between the aperture stop (S) and the third lens group (G) are changed and the aperture stop (S) is moved in an optical axis direction.

A zoom lens, comprises: in order from an object, a first lens group (G) having positive refractive power; a second lens group (G) having negative refractive power; a third lens group (G) having positive refractive power; a fourth lens group (G) having negative refractive power; and a fifth lens group (G) having positive refractive power, wherein, upon zooming from a wide-angle end state to a telephoto end state, a distance between each of lens groups and a lens group adjacent thereto changes to satisfy the following conditional expression:2.90&#x3c;|5/2|&#x3c;11.50

A first lens group (G) having positive refractive power, a second lens group (G) having negative refractive power, a third lens group (G) having positive refractive power, a fourth lens group (G) having negative refractive power, and a fifth lens group (G) having positive refractive power are arranged in order from an object, and zooming is performed by changing distances between each lens group, and the first lens group (G) is composed of three or more lenses, the fourth lens group (G) is composed of two or less lenses, and the fifth lens group (G) is composed of two or less lenses and moves to an image surface side upon zooming from a wide angle end state to a telephoto end state, and the following conditional expression (1) is satisfied.8.40&#x3c;1/(&#x2212;2)&#x2003;&#x2003;(1)

The present invention has, in order along the optical axis from the object side: a first lens group (G) that has positive refractive power; a second lens group (G) that has negative refractive power; a third lens group (G) that has positive refractive power; a fourth lens group (G) that has positive refractive power; and a fifth lens group (G). The fourth lens group (G) is constituted by a single positive lens (L), and the fifth lens group (G) is constituted by a single lens (L), which is fixed with respect to an image plane while power is being varied. The following conditional expression (1) is satisfied. 0.9&#x3c;&#x3b2;2t&#xb7;&#x3b2;3w/(&#x3b2;2w&#xb7;&#x3b2;3t)&#x3c;1.7 . . . (1), where &#x3b2;2w denotes a magnification of the second lens group (G) in the wide-angle end state, &#x3b2;3w denotes a magnification of the third lens group (G) in the wide-angle end state, &#x3b2;2t denotes a magnification of the second lens group (G) in the telephoto end state, and &#x3b2;3t denotes a magnification of the third lens group (G) in the telephoto end state.

A zoom lens ZL comprising a first lens group Ghaving negative refractive power, a second lens group Ghaving positive refractive power, and a third lens group Ghaving positive refractive power, wherein the first lens group Gincludes a first lens having negative refractive power and a second lens which is a plastic lens having positive refractive power, the second lens group Gincludes 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 Gincludes a sixth lens having positive refractive power, and the conditional expressions: 1.50&#x3c;(&#x2212;f1)/fw&#x3c;2.52, 0.4&#x3c;(&#x2212;f1)/fL2 &#x3c;0.8, n2&#xd7;n2&#xd7;&#x3bd;2&#x3c;77.0 are satisfied respectively.

Zoom lens, optical apparatus and method for manufacturing zoom lens

A zoom lens includes, in order from an object, a first lens group Ghaving negative refractive power; a second lens group Ghaving positive refractive power; and a third lens group Ghaving positive refractive power. The first lens group Gcomprises only one negative spherical lens (lens L) and one plastic positive lens (lens L) separated by an air gap. The second lens group Gcomprises three or fewer lenses, including a positive lens component (cemented lens comprising a lens Land a lens L), and one plastic negative lens (lens L). The following conditional expressions are satisfied: 0.50&#x3c;fPL/(&#x2212;fPL)&#x3c;2.50 and 0.80&#x3c;(&#x2212;f)/f&#x3c;1.35, where fPL is a focal length of the plastic positive lens forming the first lens group G, fPL is the focal length of the plastic negative lens forming the second lens group G, fis the focal length of the first lens group G, and fis the focal length of the second lens group G

Zoom lens, optical apparatus and zoom lens manufacturing method

A lens system includes, in order from an object: a first lens group having negative refractive power; and a second lens group having positive refractive power, the first lens group including, in order from the object, a lens having a negative refractive power, a plastic aspherical lens, and a lens having a positive refractive power, and the following conditional expression |fp/f|&#x3e;4.0 being satisfied, where fp denotes a focal length of the plastic aspherical lens, and fdenotes a focal length of the first lens group.

Lens system and optical apparatus having this lens system

A zoom lens comprises, in order from an object, a first lens group Ghaving negative refractive power, a second lens group Ghaving positive refractive power, and a third lens group Ghaving positive refractive power. The first lens group Gconsists of one spherical negative lens and one spherical positive lens with an air space therebetween, and the conditional expression 0.50&#x3c;(DGDGDG)/fw&#x3c;1.75 is satisfied, where DGto DGdenote the thickness of the first lens group Gto third lens group Grespectively on the optical axis, and fw denotes the focal length of the zoom lens in the wide-angle end state.

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Kawasaki, Japan

Saburo Masugi