Fuji Photo Optical Co., Ltd.

Fujifilm Corporation

Fujinon Corporation

Fujifilm Corpoation

Katsuhisa Tsutsumi

Yoshiaki Ishii

Michio Cho

Nobuaki Toyama

Ping Sun

An imaging lens consists of a front group and a rear group. The front group is composed of a lens having a negative meniscus shape with a convex surface on the object side, a negative lens, a negative lens, and a positive lens in order from the object side. The rear group is composed of a positive lens, a negative lens, a positive lens, and a positive lens in order from the object side. The imaging lens satisfies given conditional expressions.

Imaging lens and imaging apparatus equipped with the same

An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a biconcave negative single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented to form a cemented lens. The imaging lens is configured to satisfy conditional expressions (2): 0&#x3c;fg2/f&#x3c;1.3, (2b'): 0.5&#x3c;fg2/f&#x3c;1.25, and (6): 31&#x3c;&#x3bd;d2 &#x3c;70 at the same time, where fg2 is combined focal length of the second lens group, f is focal length of the entire lens system, and &#x3bd;d2 is Abbe number of the second group first lens.

Imaging lens and imaging apparatus

An imaging lens substantially consists of a negative first lens group and a positive second lens group in this order from the object side. The first lens group substantially consists of only a first lens, which is one biconcave lens. The second lens group substantially consists of, in the following order from the object side: a cemented lens, which is formed by bonding a positive lens and a negative lens, in this order from the object side, and which has a positive refractive power as a whole; an aperture stop; a positive lens; and a negative lens. The imaging lens is configured to satisfy the conditional expressions (1a): 0&#x3c;f23/f&#x3c;2.5 and (2a): 0&#x3c;f45/f&#x3c;6 at the same time.

Imaging lens, and imaging apparatus including the imaging lens

An imaging lens provided with a negative first lens group and a positive second lens group arranged in order from the object side. The first lens group is composed of a first group first lens which is a negative single lens, and the second lens group is composed of a positive second group first lens, a positive second group second lens, and a negative second group third lens arranged in order from the object side. The second group first lens is a biconvex lens, the second group second lens is a biconvex lens, the second group third lens is a meniscus lens, an aperture stop is disposed between the second group first and second lenses, and the second group second and third lenses form a cemented lens. The imaging lens satisfies conditional expressions (1): &#x2212;0.89&#x2266;f1/f&#x3c;0 and (4): 0.3&#x3c;dt1/f&#x3c;0.8.

An imaging lens substantially consists of a negative first lens group and a positive second lens group in this order from the object side. The first lens group substantially consists of only a first lens, which is one biconcave lens. The second lens group substantially consists of, in the following order from the object side: a cemented lens, which is formed by bonding a second lens, i.e., a biconvex lens, and a third lens, i.e., a negative meniscus lens, in this order from the object side, and which has a positive refractive power as a whole; an aperture stop; and a cemented lens that is formed by bonding a fourth lens, i.e., a biconvex lens and a fifth lens, i.e., a negative meniscus lens in this order from the object side and that has a positive refractive power as a whole.

An imaging lens provided with a negative first lens group and a positive second lens group arranged in order from the object side. The first lens group is composed of a first group first lens which is a biconcave negative single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens arranged in order from the object side, in which the second group second lens and the second group third lens are cemented together to form a cemented lens. When f1 and f2 are taken as the focal lengths of the first group first lens and the second group first lens respectively, the imaging lens satisfies a conditional expression (4a'): 0.62&#x3c;|f1/f2|&#x3c;0.82.

An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a negative biconcave single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented together to form a cemented lens. The imaging lens is configured to satisfy a conditional expression (3) 0.9&#x3c;dt3/f&#x3c;1.3, and further configured to satisfy conditional expression (1) 31&#x3c;&#x3bd;d2&#x3c;55 or (1'): 35&#x3c;&#x3bd;d2 and a conditional expression (2): &#x2212;10&#x3c;&#x3bd;d1&#x2212;&#x3bd;d2&#x3c;25.

An imaging lens includes a first group having a positive or negative refractive power, a second group having a positive refractive power, a third group having a positive or negative refractive power, which are sequentially arranged from the object side of the imaging lens. The first group includes an aperture stop, and the second group includes a positive lens, and a cemented lens of a positive lens and a negative lens. The third group is composed of a cemented lens of a positive lens and a negative lens, and the following formula (1) is satisfied:0.5&#x2266;2/&#x2266;1.2&#x2003;&#x2003;(1), where

A zoom lens comprises: a stationary group that is stationary at the time of variable power; and a variable power group, disposed on an image side of the stationary group, that makes a variable power operation by moving in an optical axis direction at the time of variable power, wherein the stationary group comprises: a first lens group including a negative meniscus lens and a positive lens and having a positive refractive power as a whole; and a second lens group, disposed on the image side of the first lens group, including: a negative lens group including a negative meniscus lens and a positive lens; and a positive lens group including at least one positive lens, in order from an object side, the second lens group having a positive refractive power as a whole.

Zoom lens and imaging device

A focusing group Gis disposed on an object side relative to a variator group G. The focusing group Gincludes, in order from the object side, a first group Ghaving a positive refractive power, a second group Ghaving a positive refractive power, and a third group Ghaving a positive refractive power. The first group Ghas, in order from the object side, at least one concave lens (L) and at least one convex lens. When focusing from an infinitely distant object to a close object, the second group Gand the third group Gare moved so that with respect to a change in an object distance, an amount of movement of the second group Gbecomes large in a region near infinity, while an amount of movement of the third group Gbecomes large in a close range.

Zoom lens and image pickup apparatus

An extender optical system, for insertion between a photographic main lens and a camera body for changing the focal length of the lens system as a whole to the long focus side, is formed of, in order from the object side, a first lens group having negative refractive power, a second lens group formed of a single negative lens, and a third lens group having positive refractive power. The negative lens that constitutes the second lens group is made to move in directions that are normal to the optical axis so as to correct for what would otherwise be blurred images due to vibrations. Various conditions are preferably satisfied so as to ensure high image quality over the entire field of view.

Extender optical system

A retrofocus wide-angle lens is formed of only three lens groups, in order from the object side, a first lens group of negative refractive power, a second lens group that includes a stop, and a third lens group of positive refractive power. The first lens group is at the object end of the retrofocus wide-angle lens and includes, in order from the object side, a plurality of negative lens components and a plurality of positive lens components. The first lens group includes three lens groups with particular lens features, the first of which, from the object side, also includes two lens groups with particular features. Various combinations of lens elements satisfy two conditions for ratios of absolute values of focal lengths for the various combinations of lens elements that assist in achieving excellent imaging.

Retrofocus wide-angle lens

An adaptor lens is provided for attachment between a lens of a camera and a camera body, in order to provide the camera with adaptor lens attached, a smaller effective screen size than the camera without the adaptor lens attached. The adaptor lens is formed of, in order from the object side, a front lens group and a rear lens group. The front lens group is formed of, in sequential order from the object side, a negative lens element and at least one meniscus lens element with its concave surface on the object side. The rear lens group is formed of, in sequential order from the object side, a positive lens element with a convex surface on the object side, and a negative lens element. Various conditions are, preferably, satisfied in order to maintain favorable correction of axial chromatic aberration and lateral color.

Mount conversion adaptor lens

A retro focus type wide-angle lens comprises a front group having a negative refracting power and a rear group having a positive refracting power. The front group comprises a first lens made of a negative meniscus lens, a second lens made of a biconvex lens, a third lens made of a negative meniscus lens, and a fourth lens made of a positive meniscus lens. The rear group comprises a cemented lens in which a fifth lens made of a negative lens and a sixth lens made of a positive lens are cemented together, and a seventh lens made of a positive lens. This wide-angle lens further satisfies predetermined conditional expressions.

Retro focus type wide-angle lens apparatus using the same

An attachment lens for attachment to the object side of a main camera lens in order to enable the taking of short distance shots is disclosed. The attachment lens consists of three lens elements of positive, negative, and positive refractive power, in order from the object side. The first lens element and the second lens element are coupled to form a single component. The first lens element has a convex surface on the object side. The second lens element can be of meniscus shape with its convex surface on the object side, plano-concave, or biconcave so long as its curvature matches the image side of the first lens element so that the first lens element and the second lens element may be coupled together to form a single component. Preferably, one or more specified conditions are satisfied in order maintain favorable correction of aberrations.

Growing community of inventors

Saitama-ken, Japan

Katsuhisa Tsutsumi