Nikon Corporation

Nikon Corooration

Keisuke Tsubonoya

Hiroshi Yamamoto

Tomoki Ito

Masashi Yamashita

Satoshi Miwa

Takeru Uehara

Ayumu Makida

Hiroshi Yabumoto

Toshinori Take

Hiroki Harada

A variable magnification optical system which comprises, in order from an object side, a first lens group having negative refractive power, a second lens group having positive refractive power and a third lens group; upon varying magnification, distances between the neighboring respective lens groups being varied; upon focusing, the first lens group and the second lens group being moved along the optical axis; and predetermined conditional expression(s) being satisfied, whereby the variable magnification optical system is made in small in size, and can correct superbly various aberrations.

Variable magnification optical system, optical equipment, and method for producing variable magnification optical system

An optical system (ZL()) comprises a plurality of lens groups including a first focusing lens group (G) and a second focusing lens group (G) that are disposed side by side on an optical axis, and the second focusing lens group (G) is disposed at a position closer to an image surface than the first focusing lens group (G). The first focusing lens group (G) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL()) satisfies the following conditional expression. −020<βF1/βF2<0.50 where βF1 is the lateral magnification of the first focusing lens group at the time of focusing on the infinite-distance object, and βF2 is the lateral magnification of the second focusing lens group at the time of focusing on the infinite-distance object.

Optical system, optical apparatus and method for manufacturing the optical system

An optical system (LS) includes lenses (L,L) satisfying the following conditional expressions,νLZ<35.0, and0.702<θFLZ+(0.00316×νLZ),

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

An optical system comprises, in order from an object side, a front group having positive refractive power and a rear group. Upon carrying out focusing, the front group is moved along the optical axis. A predetermined conditional expression is satisfied. Thus, an optical system having a superb optical performance being able to correct superbly various aberrations and being suitable to be used with an imaging device having highly increased number of pixels, an optical equipment equipped therewith and a manufacturing method for the optical system are provided.

Optical system, optical equipment, and manufacturing method for optical system

An optical system (LS) includes lenses (L,L) satisfying the following conditional expressions,+(0.01425×)<2.12, andν35.0,where ndLZ: a refractive index of the lens with reference to d-line, and

An optical system (ZL()) comprises a plurality of lens groups including a first focusing lens group (G) and a second focusing lens group (G) that are disposed side by side on an optical axis, and the second focusing lens group (G) is disposed at a position closer to an image surface than the first focusing lens group (G). The first focusing lens group (G) has positive refractive power, and moves toward an object along the optical axis from focusing on an infinite-distance object to focusing on a short-distance object. The second focusing lens group (G) moves toward the image surface along the optical axis from focusing on the infinite-distance object to focusing on the short-distance object. The optical system (ZL()) satisfies the following conditional expression. &#x2212;020&#x3c;&#x3b2;F1/&#x3b2;F2&#x3c;0.50 where &#x3b2;F1 is the lateral magnification of the first focusing lens group at the time of focusing on the infinite-distance object, and &#x3b2;F2 is the lateral magnification of the second focusing lens group at the time of focusing on the infinite-distance object.

An optical system (LS) Includes lenses (L22,L23) satisfying the following conditional expressions,&#x3c;35.0, and0.702&#x3c;&#x3b8;+(0.00316&#xd7;&#x3bd;),where &#x3bd;dLZ: Abbe number of the lens with reference to d-line, and

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Yokohama, Japan

Keisuke Tsubonoya