Abstract: The optical filter includes a filter edge portion forming a boundary between a region through which a light flux is transmitted and a region through which the light flux is not transmitted. The filter edge portion has a concavo-convex shape whose edge outline is formed by a continuous curved line including convex portions and concave portions alternately arranged in a direction in which the boundary extends. The curved line includes part satisfying ?a?60°. ?a represents an angle formed by a tangent at an arbitrary point on the curved line between a top point of one convex portion and a bottom point of one concave portion adjacent to the one convex portion with a tangent at the top point of the one convex portion, the angle ?a becoming larger as the arbitrary point becomes farther from the top point.

Abstract: A zoom lens includes a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a fourth lens unit having positive refractive power. The first to fourth lens units move during zooming. The first lens unit includes a cemented lens obtained by cementing negative and positive lenses, the second lens unit includes negative, negative, and positive lenses, the third lens unit includes positive and negative lenses, and the fourth lens unit includes a positive lens. Movement amounts M1 and M3 of the first and third lens units, respectively, during zooming from the wide-angle end to the telephoto end and focal lengths f1 and f3 of the first and third lens units, respectively, are appropriately set based on predetermined mathematical conditions.

Abstract: A zoom lens including first to fifth lens units in order from an object side toward an image. The refractive powers of the first to the fifth lens units are positive, negative, positive, negative and positive, respectively. The distance between the first and the second lens units is increased at the time of zooming from the wide angle end to the telephoto end, and the distance between the second and the third lens unit is decreased at the time of zooming from the wide angle end to the telephoto end. The first lens unit and the fourth lens unit are fixed for the zooming. When M2 and M3 are the amounts of movement of the second lens unit and the third lens unit at the time of zooming from the wide angle end to the telephoto end, respectively, the conditional expression; 0.2<|M2/M3|<5.0 is satisfied.

Abstract: A zoom lens includes first and second lens units having positive and negative refractive powers, an aperture stop, and third and fourth lens units having positive and negative refractive powers in order from an object side to an image side. During zooming from a wide angle end to a telephoto end, the first lens unit remains fixed, and the second and fourth lens units move. The first lens unit includes negative, positive, negative, positive, and positive lenses in order from the object side to the image side, the third and fourth lens units include two or more lenses. Focal lengths of the first and third lens units and of the entire system at the wide angle end, the thickness of the first lens unit on an optical axis, and the distance between principal points between the first and the second lens units at a wide angle end are appropriately set.

Abstract: A zoom lens including first to fifth lens units in order from an object side toward an image. The refractive powers of the first to the fifth lens units are positive, negative, positive, negative and positive, respectively. The distance between the first and the second lens units is increased at the time of zooming from the wide angle end to the telephoto end, and the distance between the second and the third lens unit is decreased at the time of zooming from the wide angle end to the telephoto end. The first lens unit and the fourth lens unit are fixed for the zooming. When M2 and M3 are the amounts of movement of the second lens unit and the third lens unit at the time of zooming from the wide angle end to the telephoto end, respectively, the conditional expression; 0.2<|M2/M3|<5.0 is satisfied.

Abstract: A zoom lens includes a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a fourth lens unit having positive refractive power. The first to fourth lens units move during zooming. The first lens unit includes a cemented lens obtained by cementing negative and positive lenses, the second lens unit includes negative, negative, and positive lenses, the third lens unit includes positive and negative lenses, and the fourth lens unit includes a positive lens. Movement amounts M1 and M3 of the first and third lens units, respectively, during zooming from the wide-angle end to the telephoto end and focal lengths f1 and f3 of the first and third lens units, respectively, are appropriately set based on predetermined mathematical conditions.

Abstract: A zoom lens comprising, in order from an object side to an image side, a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a third lens unit of a positive refractive power, and a fourth lens unit of a positive refractive power. In zooming, the first lens unit is configured fixed and the second, third, and fourth lens units are configured movable. The following conditions are satisfied where f3st is a movement amount of the third lens unit associated with zooming from a wide angle end to a telephoto end, f3 is a focal length of the third lens unit, ?2w is a lateral magnification of the second lens unit at the wide angle end, and z is a zoom ratio, 0.010<(|f3st|/f3)/z<0.045, and ?0.33<?2w<?0.20.

Abstract: A zoom lens includes positive, negative, positive, and positive lens units, and the second lens unit includes negative, negative, negative and positive lenses. The first and third lens units are fixed and the second and fourth lens units are moved in zooming. 0.01<|f2/?(fw*ft)|<0.35 and 0.070<D2/TL<0.105 are satisfied. fw and ft are focal lengths of an overall system at wide angle and telephoto ends, f2 is a focal length of the second lens unit, TL is a distance on an optical axis from a lens surface closest to an object plane to an image plane when a distance from a lens surface closest to the image plane to the image plane is aerially converted, and D2 is a distance on the optical axis from a lens surface closest to the object plane in the second lens unit to the lens surface closest to the image plane in the second lens unit.

Abstract: A zoom lens includes first and second lens units having positive and negative refractive powers, an aperture stop, and third and fourth lens units having positive and negative refractive powers in order from an object side to an image side. During zooming from a wide angle end to a telephoto end, the first lens unit remains fixed, and the second and fourth lens units move. The first lens unit includes negative, positive, negative, positive, and positive lenses in order from the object side to the image side, the third and fourth lens units include two or more lenses. Focal lengths of the first and third lens units and of the entire system at the wide angle end, the thickness of the first lens unit on an optical axis, and the distance between principal points between the first and the second lens units at a wide angle end are appropriately set.

Abstract: A zoom lens includes positive, negative, positive, and positive lens units, and the second lens unit includes negative, negative, negative and positive lenses. The first and third lens units are fixed and the second and fourth lens units are moved in zooming. 0.01<|f2/?(fw*ft)|<0.35 and 0.070<D2/TL<0.105 are satisfied. fw and ft are focal lengths of an overall system at wide angle and telephoto ends, f2 is a focal length of the second lens unit, TL is a distance on an optical axis from a lens surface closest to an object plane to an image plane when a distance from a lens surface closest to the image plane to the image plane is aerially converted, and D2 is a distance on the optical axis from a lens surface closest to the object plane in the second lens unit to the lens surface closest to the image plane in the second lens unit.

Abstract: A zoom lens comprising, in order from an object side to an image side, a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a third lens unit of a positive refractive power, and a fourth lens unit of a positive refractive power. In zooming, the first lens unit is configured fixed and the second, third, and fourth lens units are configured movable. The following conditions are satisfied where f3st is a movement amount of the third lens unit associated with zooming from a wide angle end to a telephoto end, f3 is a focal length of the third lens unit, ?2w is a lateral magnification of the second lens unit at the wide angle end, and z is a zoom ratio, 0.010<(|f3st|/f3)/z<0.045, and ?0.33<?2w<?0.20.

Abstract: In an image sensing system having an image sensing optical system, and an image sensing element for photoelectrically converting incoming light from the image sensing optical system, a predetermined pattern image for adjustment, which is specified in advance, is read by the image sensing element, and the image sensing element is driven to adjust its position on the basis of an output from said image sensing element, thereby adjusting the relative position of the image sensing element with respect to the image sensing optical system prior to an image sensing operation.

Abstract: A zoom lens comprises, in the following order from the object side to the image side, a positive first lens unit, a negative second lens unit, which moves during zooming, a positive third lens unit, and a positive fourth lens unit, which moves during zooming. The first lens unit includes a negative lens subunit and a positive lens subunit. The negative lens subunit includes at least two negative lenses each having a concave surface facing the image side and at least one positive lens arranged from the object side. The positive lens subunit includes at least one biconvex positive lens, a negative lens and at least two positive lenses arranged from the object side, or at least one biconvex positive lens, a cemented lens composed of a negative lens and a positive lens and at least one positive lens arranged from the object side.

Abstract: Disclosed is a zoom lens system, in order from an object side to an image side, including: a first lens unit having a positive optical power; a second lens unit having a negative optical power; a third lens unit having a positive optical power; and a fourth lens unit having a positive optical power, in which during zooming, intervals of the lens units are changed. In such a zoom lens system, a material having a large refractive index is adopted for a material constituting a negative lens element disposed on the most object side in the second lens unit, whereby high optical performance is realized while the whole lens system is miniaturized.

Abstract: A zoom lens comprises, in the following order from the object side to the image side, a positive first lens unit, a negative second lens unit, which moves during zooming, a positive third lens unit, and a positive fourth lens unit, which moves during zooming. The first lens unit includes a negative lens subunit and a positive lens subunit. The negative lens subunit includes at least two negative lenses each having a concave surface facing the image side and at least one positive lens arranged from the object side. The positive lens subunit includes at least one biconvex positive lens, a negative lens and at least two positive lenses arranged from the object side, or at least one biconvex positive lens, a cemented lens composed of a negative lens and a positive lens and at least one positive lens arranged from the object side.

Abstract: Disclosed is a zoom lens system, in order from an object side to an image side, including: a first lens unit having a positive optical power; a second lens unit having a negative optical power; a third lens unit having a positive optical power; and a fourth lens unit having a positive optical power, in which during zooming, intervals of the lens units are changed. In such a zoom lens system, a material having a large refractive index is adopted for a material constituting a negative lens element disposed on the most object side in the second lens unit, whereby high optical performance is realized while the whole lens system is miniaturized.

Abstract: Disclosed is a zoom lens system, in order from an object side to an image side, including: a first lens unit having a positive optical power; a second lens unit having a negative optical power; a third lens unit having a positive optical power; and a fourth lens unit having a positive optical power, in which during zooming, intervals of the lens units are changed. In such a zoom lens system, a material having a large refractive index is adopted for a material constituting a negative lens element disposed on the most object side in the second lens unit, whereby high optical performance is realized while the whole lens system is miniaturized.

Abstract: A zoom lens includes, in order from an object side to an image side: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power and an aperture stop; a fourth lens unit having negative optical power; and a fifth lens unit having positive optical power, in which, during zooming from a wide-angle end to a telephoto end, the first lens unit stays, the second lens unit moves toward the image side, and the third lens unit moves together with the aperture stop.

Abstract: A zoom lens includes, in order from an object side to an image side: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power and an aperture stop; a fourth lens unit having negative optical power; and a fifth lens unit having positive optical power, in which, during zooming from a wide-angle end to a telephoto end, the first lens unit stays, the second lens unit moves toward the image side, and the third lens unit moves together with the aperture stop.

Abstract: A zoom lens system is disclosed, comprising, in order from an object side to an image side, a first lens unit of positive optical power, a second lens unit of negative optical power, a third lens unit of positive optical power, and a fourth lens unit of positive optical power, wherein the second and fourth lens units are moved during zooming. The third lens unit consists of a first lens subunit of positive optical power, an aperture stop, and a second lens subunit having one or more negative lens elements and one or more positive lens elements, in order from the object to the image sides. Optical parameters including the focal length of each lens unit, lens shapes, the lens structure of each lens unit are specified to realize a zoom lens system with a smaller size of the entire lens system and higher optical performance.