Abstract: An optical system includes one or more positive lenses and one or more negative lenses. The first positive lens is a positive lens disposed closest to an object among the one or more positive lenses. The first negative lens is a negative lens that is disposed on an image side of the first positive lens and disposed closest to the object among the one or more negative lenses. At least one of an object side surface and an image side surface of the first positive lens is an aspherical surface. At this time, a relationship between a total lens length of the optical system L0, a focal length of the optical system L0, and a distance Dpn on an optical axis from the image side surface of the first positive lens to an object side surface of the first negative lens is defined.

Abstract: An optical system used in an imaging apparatus includes an optical element. In a case where the optical element is disposed on a magnification side with respect to an intersection point of an optical axis and a chief paraxial ray, the optical element is a negative lens, and in a case where the optical element is disposed on a reduction side with respect to the intersection point, the optical element is a positive lens. The optical element is configured to satisfy all of the following conditional expressions: 30??d?40 1.225?[nd?(14.387/?d)]?1.276 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d represents an Abbe number of the optical element, ?gF is a partial dispersion ratio of the optical element for g-line and F-line, and nd is a refractive index of the optical element for d-line.

Abstract: A zoom lens includes, in order from an object side: a positive first unit; a negative second unit; and a rear group. The rear group includes: a positive object-side unit, which is arranged closest to the object side; a negative rear-side unit, which is arranged closest to the image side in the zoom lens; and a negative middle unit, which is arranged adjacent to the rear-side unit and on the object side of the rear-side unit. The first unit, the middle unit, and the rear-side unit are configured to move toward the object side during zooming from a wide angle end. Further, focal lengths of the second unit and the middle unit, movement amounts of the middle unit, the rear-side unit, the object-side unit, and the first unit during zooming from the wide angle end to the telephoto end are each appropriately set.

Abstract: An optical system includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a positive refractive power, and a third lens unit having a negative refractive power. The second lens unit moves during focusing and a distance between adjacent lens units changes. The second lens unit includes a cemented lens closest to an object. The cemented lens includes a positive lens and a negative lens disposed on the image side of the positive lens. A predetermined condition is satisfied.

Abstract: A zoom lens including a first lens unit that has a positive refractive power, a second lens unit that has a negative refractive power, and at least one lens unit, in which the first lens unit, the second lens unit, and at least one lens unit are disposed from an object side to an image side in the above order. The first lens unit is formed of a single piece of lens element, and the zoom lens includes a positive lens on a side closest to an image. An Abbe number of the positive lens, back focuses at a wide angle end and a telescopic end, and focal lengths of the zoom lens at the wide angle end and the telescopic end are each set appropriately.

Abstract: Provided is an optical system, including, in order from an object side to an image side: a first lens unit having a positive refractive power; a second lens unit having a positive refractive power; a third lens unit having a negative refractive power; and a fourth lens unit having a positive refractive power, in which the second lens unit is configured to move in an optical axis direction during focusing, in which the third lens unit is configured to move, during image blur correction, in a direction having a vertical direction component with respect to an optical axis, and in which a configuration of the first lens unit and arrangement of an aperture stop and the third lens unit are each appropriately set.

Abstract: An optical system includes, in order from an object side to an image side, a first lens unit having positive refractive power, and a second lens unit having negative refractive power, wherein the first lens unit moves and the second lens unit does not move during focusing, wherein the first lens unit includes a positive lens arranged closest on the object side of the first lens unit, wherein the second lens unit includes three or more lenses including at least two negative lenses, wherein the first lens unit consists of a first subunit having positive refractive power, a second subunit having negative refractive power, and a third subunit having positive refractive power arranged in order from the object side to the image side, and wherein predetermined conditional expressions are satisfied.

Abstract: A zoom lens includes lens units whose interval between adjacent units is changed during zooming, wherein the lens units consist of, in order from an object side, a positive first unit, an negative intermediate lens group including a unit, a positive (n?1)-th unit, and a positive n-th unit, wherein the first unit moves during zooming, wherein an interval between the (n?1)-th and n-th units is smaller at telephoto end than at wide angle end, wherein the n-th unit includes positive lenses LPL made of a material having proper Abbe number, wherein the n-th lens unit includes a positive lens LPH arranged on the image side of the lenses LPL and made of a material having proper refractive index and wherein a distance between lens surfaces on the most-object side and on the most-image side of the n-th lens unit, and back focus at the wide angle end are properly set.

Abstract: The lens apparatus includes an optical system, a voltage transformation unit, and an actuator. A first lens unit of the optical system is moved toward the object side during zooming from a wide-angle end to a telephoto end. The voltage transformation unit includes coils. The actuator is configured to be driven by a voltage output from the voltage transformation unit and to move a part of the lens units in the optical system during focusing. The coil is disposed at a position that is separated from a position of a most object-side surface of the optical system at the wide-angle end, toward the image side by a maximum or more moving amount of the first lens unit, and is closer to the object side than a most image-side surface of the optical system at the wide-angle end.

Abstract: A zoom lens includes, in order from an object side: a positive first unit; a negative second unit; and a rear group. The rear group includes: a positive object-side unit, which is arranged closest to the object side; a negative rear-side unit, which is arranged closest to the image side in the zoom lens; and a negative middle unit, which is arranged adjacent to the rear-side unit and on the object side of the rear-side unit. The first unit, the middle unit, and the rear-side unit are configured to move toward the object side during zooming from a wide angle end. Further, focal lengths of the second unit and the middle unit, movement amounts of the middle unit, the rear-side unit, the object-side unit, and the first unit during zooming from the wide angle end to the telephoto end are each appropriately set.

Abstract: Provided is a zoom lens, including, in order from an object side: a positive first lens unit; a negative second lens unit; an intermediate lens unit including at least one lens unit; a positive (N?1)-th lens unit; and a negative N-th lens unit, in which the (N?1)-th lens unit is configured to move for focusing, and in which a focal length fLM of the intermediate lens unit at a wide angle end, a focal length f(N?1) of the (N?1)-th lens unit, which consists of a single lens element, a focal length fN of the N-th lens unit, a distance DN on an optical axis from a lens surface closest to the object side of the N-th lens unit to a lens surface closest to the image side of the N-th lens unit, and a back focus BFw at the wide angle end are each appropriately set.

Abstract: An optical system includes a negative lens satisfying the following conditional expressions: 30??d?40, 1.225?[nd?(14.387/?d)]?1.276, and 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d is an Abbe number of the negative lens, ?gF is a partial dispersion ratio of the negative lens at a g-line and an F-line, and nd is a refractive index of the negative lens at a d-line.

Abstract: A conversion lens having a negative refractive power includes a positive lens GP. The positive lens GP satisfies all the following conditional expressions: 30??d?40, 1.225?[nd?(14.387/?d)]?1.276, and 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d is an Abbe number of the positive lens GP, ?gF is a partial dispersion ratio of the positive lens GP for g-line and F-line, and nd is a refractive index of the positive lens GP for d-line.

Abstract: An optical system includes an optical element. When the optical element is disposed on a magnification side with respect to an intersection point between an optical axis and a chief paraxial ray, the optical element is a positive lens. When the optical element is disposed on a reduction side with respect to the intersection point, the optical element is a negative lens. The optical element satisfies all of the following conditional expressions: 30??d?40 1.225?[nd?(14.387/?d)]?1.276 0.4300?[?gF?(2.9795/?d)]?0.5010 where ?d is Abbe number of the optical element, ?gF is a partial dispersion ratio of the optical element for g-line and F-line, and nd is a refractive index of the optical element for d-line.

Abstract: A zoom lens includes lens units whose interval between adjacent units is changed during zooming, wherein the lens units consist of, in order from an object side, a positive first unit, an negative intermediate lens group including a unit, a positive (n?1)-th unit, and a positive n-th unit, wherein the first unit moves during zooming, wherein an interval between the (n?1)-th and n-th units is smaller at telephoto end than at wide angle end, wherein the n-th unit includes positive lenses LPL made of a material having proper Abbe number, wherein the n-th lens unit includes a positive lens LPH arranged on the image side of the lenses LPL and made of a material having proper refractive index and wherein a distance between lens surfaces on the most-object side and on the most-image side of the n-th lens unit, and back focus at the wide angle end are properly set.

Abstract: The zoom lens according to the present invention includes a plurality of lens units consisting of front and rear groups having negative and positive refractive powers at a wide angle end (WAE), respectively. An interval between front and rear groups on an optical axis is longest among all intervals between adjacent ones of plurality of lens units at WAE. The rear group is disposed at an image side of front group and includes a plurality of lens units including a negative lens unit LN (LULN) disposed closest to image side. The LULN includes negative and positive lenses disposed closest to object and image sides in LULN, respectively. A focal length of LULN, a focal length of zoom lens at WAE, a distance on optical axis between a lens surface closest to object side and that closest to image side in LULN, and a back focus at WAE are appropriately set.

Abstract: A zoom lens including a first lens unit that has a positive refractive power, a second lens unit that has a negative refractive power, and at least one lens unit, in which the first lens unit, the second lens unit, and at least one lens unit are disposed from an object side to an image side in the above order. The first lens unit is formed of a single piece of lens element, and the zoom lens includes a positive lens on a side closest to an image. An Abbe number of the positive lens, back focuses at a wide angle end and a telescopic end, and focal lengths of the zoom lens at the wide angle end and the telescopic end are each set appropriately.

Abstract: Provided is a zoom lens, including, in order from an object side: a positive first lens unit; a negative second lens unit; an intermediate lens unit including at least one lens unit; a positive (N?1)-th lens unit; and a negative N-th lens unit, in which the (N?1)-th lens unit is configured to move for focusing, and in which a focal length fLM of the intermediate lens unit at a wide angle end, a focal length f(N?1) of the (N?1)-th lens unit, which consists of a single lens element, a focal length fN of the N-th lens unit, a distance DN on an optical axis from a lens surface closest to the object side of the N-th lens unit to a lens surface closest to the image side of the N-th lens unit, and a back focus BFw at the wide angle end are each appropriately set.

Abstract: Provided is a zoom lens, including: a front lens group only including one or more positive lens unit; a magnification-varying lens unit consisting of a negative lens unit which moves during zooming; and a positive rear lens group including a plurality of lens units, in which an interval between adjacent lens units is changed during zooming, in which front lens group includes a positive focusing unit La, in which rear lens group includes a focusing unit Lb, in which focusing unit La moves toward object side and focusing unit Lb moves toward one of object side and image side, during focusing from infinity to close distance, and a movement amount of focusing unit La at a wide angle end during focusing from infinity to closest distance, and a movement amount of focusing unit La at a telephoto end during focusing from infinity to closest distance are each appropriately set.

Abstract: An optical system used in an imaging apparatus includes an optical element. In a case where the optical element is disposed on a magnification side with respect to an intersection point of an optical axis and a chief paraxial ray, the optical element is a negative lens, and in a case where the optical element is disposed on a reduction side with respect to the intersection point, the optical element is a positive lens. The optical element is configured to satisfy all of the following conditional expressions: 30??d?40 1.225?[nd?(14.387/?d)]?1.276 0.4300?[?gF?(2.9795/?d)]?0.5010, where ?d represents an Abbe number of the optical element, ?gF is a partial dispersion ratio of the optical element for g-line and F-line, and nd is a refractive index of the optical element for d-line.