Abstract: Provided are a lens device, an imaging apparatus, and a filter unit capable of suppressing occurrence of ghosts and flares. The lens device includes a first optical filter and a second optical filter in order from an object side in an optical path. The first optical filter is composed of an optical filter (for example, a band-pass filter) that has a light transmission band in a specific wavelength region. The second optical filter is composed of an optical filter (band-stop filter) that has a light absorption band in a wavelength region which is different from the light transmission band of the first optical filter.

Abstract: The zoom lens consists of a first lens group, a front group, a middle group, and a rear group, in order from an object side. The first lens group has a positive refractive power and includes a negative lens and a positive lens, successively in order from a position closest to the object side to an image side. The front group consists of one or more lens groups that move during zooming and has a negative refractive power as a whole throughout an entire zoom range. The middle group includes only one lens group as a lens group. The rear group consists of a plurality of lens groups. An aperture stop is disposed between a lens surface closest to the image side in the front group and a lens surface closest to the object side in the rear group. The zoom lens satisfies predetermined conditional expressions.

Abstract: The variable magnification optical system consists of, in order from an object side to an image side, a first lens group that has a positive refractive power, a plurality of lens groups, and a final lens group that has a positive refractive power. During changing magnification, a spacing between the first lens group and the lens group closest to the object side among the plurality of lens groups changes, all spacings between adjacent lens groups in the plurality of lens groups change, and a spacing between the lens group closest to the image side and the final lens group among the plurality of lens groups changes.

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 zoom lens consists of, in order from an object side: a positive first lens group that does not move during zooming; a middle group that consists of two or more movable lens groups moving during zooming; and a subsequent group that has a lens group including a stop at a position closest to the object side. The middle group has at least two negative movable lens groups. The subsequent group includes at least one positive LA lens that satisfies predetermined conditional expressions relating to the refractive index, the Abbe number, and the partial dispersion ratio.

Abstract: The zoom lens consists of, in order from an object side: a positive first lens group that does not move during zooming; a middle group that consists of two or more movable lens groups moving during zooming; and a subsequent group that has a lens group including a stop at a position closest to the object side. The middle group has at least two negative movable lens groups. At least one negative movable lens group in the middle group includes at least one negative LN lens which satisfies predetermined conditional expressions relating to the refractive index, the Abbe number, and the partial dispersion ratio.

Abstract: The imaging lens consists of, in order from an object side, a negative first lens group immovable during focusing, a stop and a positive second lens group moving during focusing. The first lens group consists of, in order from the object side, a meniscus lens having a convex surface toward the object side, a negative meniscus lens having a convex surface toward the object side, a negative lens, a biconvex lens, a negative meniscus lens having a convex surface toward the object side, and a positive lens having a convex surface toward the object side. Predetermined conditional expressions concerning a focal length f of the entire system, a focal length f1 of the first lens group, and a shape of an air lens between first and second lenses of the first lens group from an image side are satisfied.

Abstract: Provided are an image processing device, an image processing system, an image processing method, and an imaging optical system group capable of suppressing an increase in costs and appropriately restoring an image. In the imaging optical system, in a case where a first MTF curve M1 indicating an MTF value in a first azimuth direction with respect to an amount of defocus from a focal position is compared with a second MTF curve M2 indicating an MTF value in a second azimuth direction with respect to the amount of defocus from the focal position, a ratio of a peak value P1 of the first MTF curve M1 to a peak value P2 of the second MTF curve M2 is equal to or greater than 2, and a ratio of a half-value width HW2 of the second MTF curve M2 to a half-value width HW1 of the first MTF curve M1 is equal to or greater than 1.25. The restoration filter is a common filter corresponding to a representative value of transfer functions in a plurality of same type imaging optical systems.

Abstract: The imaging lens consists of, in order from the object side, a positive first lens group that has a positive refractive power and remains stationary during focusing, and a second lens group that moves toward an image side during focusing from a distant object to a close-range object. The first lens group has, successively in order from a position closest to the image side, a first-b sub-lens group having a positive refractive power, and an aperture stop. The imaging lens satisfies predetermined conditional expressions relating to the first-b sub-lens group, the second lens group, and the like.

Abstract: The imaging lens consists of, in order from the object side, a first lens group, an aperture stop, a second lens group having a positive refractive power. During focusing from a distant object to a close-range object, the first lens group remains stationary, and the aperture stop and the second lens group integrally move to the object side. The imaging lens satisfies predetermined conditional expressions relating to a focal length of the whole system, a focal length of the first lens group, a principal point position of the second lens group, a focal length of the second lens group, a back focal length, and the like.

Abstract: For causing a near-infrared light image obtained through imaging in a second imaging mode to be easily viewed while suppressing an increase in size and number of components, in a case where an imaging unit is operating in the second imaging mode, a change region where there is a change is detected through comparison with the second image data that the imaging unit has acquired before the second image data, from within the second image data acquired by the imaging unit. Combination image data obtained by combining the change region image data corresponding to the change region within the second image data with background image data of a color image generated on the basis of first image data acquired in a first imaging mode immediately before the second imaging mode by the imaging unit and corresponding to a background region different from the change region within the second image data is generated on the basis of the detection result of the change region.

Abstract: An image processing device, an image processing system, and an image processing method capable of easily correcting image deterioration caused by nonuniform optical characteristics around an optical axis of a lens according to a position in a rotational direction of a lens barrel are provided.

Abstract: The zoom lens consists of, in order from an object side: a positive first lens group that does not move during zooming; a middle group that consists of two or more movable lens groups moving during zooming; and a subsequent group that has a lens group including a stop at a position closest to the object side. The middle group has at least two negative movable lens groups. At least one negative movable lens group in the middle group includes at least one negative LN lens which satisfies predetermined conditional expressions relating to the refractive index, the Abbe number, and the partial dispersion ratio.

Abstract: The zoom lens consists of, in order from an object side: a positive first lens group that does not move during zooming; a middle group that consists of two or more movable lens groups moving during zooming; and a subsequent group that has a lens group including a stop at a position closest to the object side. The middle group has at least two negative movable lens groups. The subsequent group includes at least one positive LA lens that satisfies predetermined conditional expressions relating to the refractive index, the Abbe number, and the partial dispersion ratio.

Abstract: The imaging lens includes, in order from the object side, a first lens group that remains stationary during focusing; a diaphragm; and a positive second lens group that moves to the object side during focusing from a long range to a close range. The first lens group includes, in order from the object side: a negative meniscus lens that has an absolute value of a radius of curvature of an image side surface smaller than that of an object side surface, a negative lens, a positive lens, and a negative lens. The second lens group includes five or less lenses, and includes: a positive Z lens that is formed continuously in order from a most image side; a negative Y lens that has an absolute value of a radius of curvature of an object side surface smaller than that of an image side surface; and a positive X lens.

Abstract: The imaging lens includes, in order from the object side, a first lens group that remains stationary during focusing; a diaphragm; and a positive second lens group that moves to the object side during focusing from a long range to a close range. The second lens group includes a positive Z lens that is formed continuously in order from a most image side, a negative Y lens that has an absolute value of a radius of curvature of an object side surface smaller than an absolute value of a radius of curvature of an image side surface, a positive X lens, and a negative W lens that has an absolute value of a radius of curvature of an image side surface smaller than that of an object side surface. The imaging lens satisfies a conditional expression about of the radii of curvature of the X lens and the W lens.

Abstract: The imaging lens consists of, in order from an object side, a negative first lens group immovable during focusing, a stop and a positive second lens group moving during focusing. The first lens group consists of, in order from the object side, a meniscus lens having a convex surface toward the object side, a negative meniscus lens having a convex surface toward the object side, a negative lens, a biconvex lens, a negative meniscus lens having a convex surface toward the object side, and a positive lens having a convex surface toward the object side. Predetermined conditional expressions concerning a focal length f of the entire system, a focal length f1 of the first lens group, and a shape of an air lens between first and second lenses of the first lens group from an image side are satisfied.

Abstract: Provided are an image processing device, an image processing system, an image processing method, and an imaging optical system group capable of suppressing an increase in costs and appropriately restoring an image. In the imaging optical system, in a case where a first MTF curve M1 indicating an MTF value in a first azimuth direction with respect to an amount of defocus from a focal position is compared with a second MTF curve M2 indicating an MTF value in a second azimuth direction with respect to the amount of defocus from the focal position, a ratio of a peak value P1 of the first MTF curve M1 to a peak value P2 of the second MTF curve M2 is equal to or greater than 2, and a ratio of a half-value width HW2 of the second MTF curve M2 to a half-value width HW1 of the first MTF curve M1 is equal to or greater than 1.25. The restoration filter is a common filter corresponding to a representative value of transfer functions in a plurality of same type imaging optical systems.

Abstract: An optical system has the entire angle of view at a wide-angle end of not smaller than 90 degrees. A spatial frequency at which an MTF of the optical system acquired using an evaluation wavelength in a region of an image formation plane in which the distance from the center of the image formation plane is not less than 80% and less than 95% of half of the length of a diagonal line of an imaging surface of an imaging element image is not more than 30% is higher at the wide-angle end than at a telephoto end. When F??(Fw×Ft) is satisfied (where F indicates the focal length of the optical system when the target image is captured, Fw indicates the focal length at the wide-angle end, and Ft indicates the focal length at the telephoto end), a sharpening processing unit performs a restoration process based on an optical transfer function of the optical system as a sharpening process.

Abstract: The imaging lens consists of, in order from the object side, a positive first lens group that has a positive refractive power and remains stationary during focusing, and a second lens group that moves toward an image side during focusing from a distant object to a close-range object. The first lens group has, successively in order from a position closest to the image side, a first-b sub-lens group having a positive refractive power, and an aperture stop. The imaging lens satisfies predetermined conditional expressions relating to the first-b sub-lens group, the second lens group, and the like.