A wide-angle lens includes a front group, an aperture, a rear group, and an infrared cut filter. The front group includes a first lens and a second lens arranged in order from a side closest to an object to an image side. In the wide-angle lens, an anti-reflection layer having a reflectance of 1.5% or less in a wavelength range from nm to 850 nm is provided on a lens surface of the first lens on the image side to suppress an occurrence of a ghost caused by light passing through a peripheral portion of the lens surface. Therefore, even if a film forming the anti-reflection layer is thinner than an appropriate value at the peripheral portion of the lens surface, the anti-reflection layer appropriately prevents reflection of light in a long wavelength range.

An optical system comprises, in order from an object side, a front group GF having positive refractive power, an aperture stop S and a rear group GR. The front group FR comprises a front focusing group GFF having positive refractive power, and the rear group GR comprises a rear focusing group GRF having positive refractive power, upon focusing the front focusing group GFF and the rear focusing group GRF being moved toward the object side, and a predetermined condition being satisfied. Thus, an optical system having a superb optical performance, an optical equipment equipped therewith and a manufacturing method for the optical system are provided.

An optical system comprises, in order from an object side, a front group GF having positive refractive power, an aperture stop S and a rear group GR. The front group FR comprises a front focusing group GFF having positive refractive power, and the rear group GR comprises a rear focusing group GRF having positive refractive power, upon focusing the front focusing group GFF and the rear focusing group GRF being moved toward the object side, and a predetermined condition being satisfied. Thus, an optical system having a superb optical performance, an optical equipment equipped therewith and a manufacturing method for the optical system are provided.

A lens system, a photographing apparatus, and a moving body. The lens system may consist essentially of a first lens group having positive refractive power, an aperture stop, and a second lens group having positive refractive power in order from an object side to an image side. When focusing from an infinity focus state to a close object focus state, the first lens group and the second lens group may be configured to move from the image side to the object side with a fixed interval between the first lens group and the second lens group on an optical axis. The first lens group may consist essentially of three or more lenses, which may include one or more cemented lenses and one aspherical meniscus lens with a convex surface facing the object side in order from the object side.

An imaging apparatus moves a lens in the optical axis direction with respect to the initialization position, and images a subject. The imaging apparatus includes a first lens, a second lens, a driving unit, a first position detection sensor, a second position detection sensor, a third position detection sensor, and a control unit. The driving unit moves the first lens and second lens in the optical axis direction. The first position detection sensor detects the position of the first lens. The second position detection sensor detects the position of the second lens. The third position detection sensor detects the position of the first lens and the position of the second lens. On the basis of the output from the third position detection sensor, the control unit executes the initializing processing of determining the initialization positions of the first lens and second lens.

An imaging lens is constituted by, in order from the object side to the image side: a positive first lens group; a stop; a negative second lens group; and a positive third lens group. Only the second lens group moves in the direction of the optical axis to perform focusing operations. The second lens group is constituted by one or two positive lenses and one negative lens. The third lens group is constituted by, in order from the object side to the image side, two or three positive lenses and one negative lens.

An imaging lens is constituted by, in order from the object side to the image side: a positive first lens group; a stop; a negative second lens group; and a positive third lens group. Only the second lens group moves in the direction of the optical axis to perform focusing operations. The first lens group is constituted by, in order from the object side to the image side, a first lens group front group and a first lens group rear group. The first lens group front group is constituted by, in order from the object side to the image side, one positive lens and one negative lens, the first lens group rear group includes at least two negative lenses and at least three positive lenses. The second lens group is constituted by one or two positive lenses and one negative lens.

An image-capturing optical system includes an aperture stop; a first lens group closer to an object than the aperture stop and composed of multiple glass lenses including a meniscus lens having a negative power closest to the object within the first lens group, and a second lens group closer to an image than the aperture stop. The second lens group includes a first plastic lens, a second plastic lens adjacent to the first plastic lens and closer to the image than the first plastic lens. The second plastic lens has a surface facing the image, in which curvature is positive in vicinity of the optical axis and an absolute value of the curvature increases within a range from the vicinity of the optical axis to an off-axis area of the surface, and a glass lens having positive power closest to the image within the second lens group.

An image-capturing optical system includes an aperture stop; a first lens group closer to an object than the aperture stop and composed of multiple glass lenses including a meniscus lens having a negative power closest to the object within the first lens group, and a second lens group closer to an image than the aperture stop. The second lens group includes a first plastic lens, a second plastic lens adjacent to the first plastic lens and closer to the image than the first plastic lens. The second plastic lens has a surface facing the image, in which curvature is positive in vicinity of the optical axis and an absolute value of the curvature increases within a range from the vicinity of the optical axis to an off-axis area of the surface, and a glass lens having positive power closest to the image within the second lens group.

The imaging lens consists of a positive first lens group, a stop, and a positive second lens group in order from the object side to the image side. An Ln lens, which is a negative lens having an absolute value of a curvature radius of an image side surface smaller than an absolute value of a curvature radius of an object side surface, is disposed at a position closest to the image side in the first lens group. In a Cartesian coordinate system in which a horizontal axis is an Abbe number ν and a vertical axis is a partial dispersion ratio θ, ν and θ of the Ln lens are included in a predetermined region.