Abstract:
The zoom lens includes, in order from an object side, a focusing part, a variable magnification part, an aperture stop, and an imaging part. The zoom lens is switchable between a first state and a second state by replacing a part of the imaging part that is provided to be replaceable. In response to switching from the first state to the second state, a focal length of the zoom lens changes to a long focal length side while keeping an image formation position constant. The zoom lens satisfies predetermined conditional expressions.
Abstract:
A restoration processing unit performs a restoration process based on an optical transfer function of an optical system for a target image. The entire angle of view of the optical system is greater than 90 degrees. A light amount evaluation region of the optical system is a region in which a distance from the center of an image formation plane is not less than 80% of half of the length of a diagonal line of an imaging surface of an imaging element. When a first evaluation wavelength is used, the ratio of the amount of light in the light amount evaluation region to the amount of light in a region of the optical system corresponding to the center of the image formation plane is not less than 25%. When a second evaluation wavelength is used, the value of the MTF of the optical system acquired at half of the Nyquist frequency of the imaging element is not less than 15%.
Abstract:
An imaging lens is constituted essentially by six lenses, including: a first lens having a positive refractive power and a convex surface toward the object side; a second lens having a negative refractive power; a third lens having a positive refractive power; a fourth lens having a positive refractive power; a fifth lens of a biconcave shape; and a sixth lens having a negative refractive power, provided in this order from the object side. The imaging lens satisfies predetermined conditional formulae.
Abstract:
An imaging lens is substantially constituted by five lenses, including: a positive first lens having a convex surface toward the object side; a negative second lens of a meniscus shape with a concave surface toward the object side; a positive third lens of a meniscus shape with a convex surface toward the object side; a positive fourth lens of a meniscus shape with a concave surface toward the object side; and a negative fifth lens having a concave surface toward the image side, the surface thereof toward the image side being of an aspherical shape having at least one inflection point within a range from an intersection of a principal light ray at a maximum angle of view with the surface toward the image side inwardly toward the optical axis in the radial direction, provided in this order from the object side. The imaging lens satisfies a predetermined conditional formula.
Abstract:
A zoom lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; and a subsequent group that has a plurality of lens groups, wherein: the zoom lens includes an aperture stop at a position closer to the image side than a lens surface closest to the image side in the second lens group, a lens group closest to the image side in the subsequent group includes at least one negative lens of which an object side lens surface is a concave surface being in contact with air, during zooming, a spacing between the first lens group and the second lens group changes, a spacing between the second lens group and the subsequent group changes, and spacings between all adjacent lens groups in the subsequent group change.
Abstract:
A zoom lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; an intermediate lens group that consists of one or two lens groups; and a final lens group, wherein during zooming, the second lens group moves along an optical axis, and all distances between adjacent lens groups change.
Abstract:
The variable magnification optical system consists of a positive first lens group, an intermediate group, and a subsequent group in order from an object side to an image side, and does not form an intermediate real image in the entire zooming range. During zooming in a first zooming mode, a distance between the first lens group and the intermediate group changes, all distances between adjacent lens groups in the intermediate group change, a distance between the intermediate group and the subsequent group changes, and all distances between adjacent lens groups in the subsequent group are stationary. During zooming in the second zooming mode, all lens groups in the first lens group and the intermediate group are stationary, and all the distances of the adjacent lens groups in the subsequent group change. The zooming in the first zooming mode and the zooming in the second zooming mode can be independent.
Abstract:
The zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming, the second lens group, the third lens group, and the fourth lens group move. The first lens group consists of, in order from an object side, a negative first a lens group, a positive first b lens group that moves during focusing, and a positive first c lens group. The second lens group includes one positive lens and one or more negative lenses successively in order from a most object side to an image side.
Abstract:
The zoom lens consists of, in order from an object side: a first lens group that has a positive refractive power; a second lens group that has a positive refractive power; a third lens group that has a negative refractive power; a fourth lens group; and a fifth lens group that has a positive refractive power. The first lens group and the fifth lens group remain stationary with respect to an image plane during zooming. The second lens group, the third lens group, and the fourth lens group are moved by changing distances between the lens groups and adjacent groups in a direction of an optical axis during zooming, and are positioned to be closer to the image side at a telephoto end than at a wide-angle end. Conditional Expression (1) is satisfied. 0.8
Abstract:
An imaging lens is constituted essentially by six lenses, including, in order from the object side to the image side: a first lens having a positive refractive power and is of a meniscus shape with a concave surface toward the object side; a second lens having a positive refractive power and a convex surface toward the object side; a third lens having a negative refractive power; a fourth lens; a fifth lens; and a sixth lens having a negative refractive power. An aperture stop is positioned at the object side of the surface toward the object side of the third lens.