Abstract: An image forming lens system includes an aperture stop, and an image-side lens unit group which is disposed on an image side of the aperture stop. The image-side lens unit group includes a first image-side lens unit having a negative refractive power, a second image-side lens unit having a positive refractive power, and a third image-side lens unit having a negative refractive power. Any one of the first image-side lens unit, the second image side lens unit, and the third image-side lens unit is a focusing lens unit which moves along the optical axis at the time of focusing, and the following conditional expression (1) is satisfied: 0.06<|ffo/f|<0.4 ??(1) where, f denotes a focal length of the image forming lens system at the time of focusing at an object at infinity, and ffo denotes a focal length of the focusing lens unit.

Abstract: A telephoto lens includes first, second and third lens units. The first lens unit has positive refractive power front-side lens, first rear-side lens, and second rear-side lens units. The first lens unit has a negative lens element satisfying 0.5?|f/fLn|?4.908. The third lens unit has positive and negative lens elements. The first rear-side lens unit includes a predetermined negative lens element and a positive lens element. Lens elements of the front-side lens unit include at least one positive lens element. The second rear-side lens unit has a positive lens element. Conditional Expression 0.247??GFGR1/f?0.5 is satisfied. f and fLn are focal lengths of the telephoto lens and predetermined negative lens element. ?GFGR1 is an axial distance from an object-side surface in the front-side lens unit to an object-side surface in the first rear-side lens unit.

Abstract: A zoom optical system includes a front-side lens unit, an intermediate lens unit, and a rear-side lens unit. The front-side lens unit includes a first front unit and a second front unit, and a distance between the first front unit and the second front unit is wider at a telephoto end than at a wide angle end. The intermediate lens unit includes a first intermediate unit and a second intermediate unit, and a distance between the first intermediate unit and the second intermediate unit is narrower at the telephoto end than at the wide angle end. A distance between the second intermediate unit and a lens unit adjacent to the second intermediate unit varies. The second intermediate unit moves at the time of focusing, and the following conditional expressions (1) and (2) are satisfied: 0.9?LTLT/LTLW?1.17??(1) 4.2?KMBT?20.0??(2).

Abstract: A zoom lens includes in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a first lens component in the predetermined lens unit moves perpendicularly with respect to an optical axis and is fixed at the time of zooming, and a second lens component is disposed, leaving an air space on an image side of the first lens component, and a sign of a refractive power of the second lens component differs from a sign of a refractive power of the first lens component, and the following conditional expression (1) is satisfied. 3.

Abstract: A zoom lens includes a front unit having a negative refractive power; and a rear unit having a positive refractive power, which includes an aperture stop. The front unit includes a first negative refractive power lens, a second negative refractive power lens, and a third positive refractive power lens. The first lens is nearest to an object, and has a meniscus shape with a convex surface directed toward the object side, and the second lens is on an image side of the first lens, and has a meniscus shape with a convex surface directed toward the object side. The rear unit includes a first lens unit A and a second lens unit B, wherein when zooming from a wide angle end to a telephoto end, a distance between the front unit and the rear unit narrows, and a distance between the first lens unit A and the second lens unit B changes. The first lens unit A includes a first sub-lens unit having a positive refractive power, the aperture stop, and a second sub-lens unit.

Abstract: A zoom lens includes in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power. The first lens unit includes a positive lens, and the second lens unit includes a positive lens, and the following conditional expressions (1), (2), (3), and (4) are satisfied: ?0.015?Tp2G_min_p?0.015??(1), 70.3??d1G_max_p??(2), 1.76?nd2G_max_p?2.3??(3), and 0.3?|f2/f3|?0.9??(4).

Abstract: A zoom lens includes a front-side lens unit, a rear-side lens unit, and an aperture stop. The front-side lens unit includes either one lens unit having a negative refractive power or two lens units having a negative refractive power, and has a negative refractive power as a whole. The rear-side lens unit is disposed on an image side of the front-side lens unit, and has a positive refractive power as a whole at a telephoto end. The rear-side lens unit includes a plurality of lens units, and includes an object-side positive lens unit having a positive refractive power which is disposed nearest to object and the following conditional expressions (1), (2), and (3) are satisfied: 1.2?|MGB_t|?6??(1), 10??dGn_min_p?27??(2), and ?0.03?TpGn_min_p?0.014??(3).

Abstract: A zoom lens comprises four lens unit, and at the time of zooming, each of a distance between a first positive lens unit and a first negative lens unit and a distance between a second negative lens unit and a second positive lens unit changes, and a distance between the first positive lens unit and the second negative lens unit widens more at the telephoto end than at the wide angle end, and the first positive lens unit includes an object-side sub-lens unit and an image-side sub-lens unit, and an aperture stop is disposed between the object-side sub-lens unit and the image-side sub-lens unit, and the first negative lens unit includes a negative lens and a positive lens, and a refracting surface nearest to an image in the first negative lens unit is concave toward the image side, and a refracting surface nearest to an object in the second positive lens unit is concave toward the object side, and a refracting surface nearest to the image in the second positive lens unit is convex toward the image side, and the z

Abstract: A zoom lens includes in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a rear-side lens unit, and an aperture stop. The second lens unit includes a first sub-unit having a negative refractive power and a second sub-unit having a negative refractive power, and the rear-side lens unit includes a third lens unit having a positive refractive power which is disposed nearest to object. The first lens unit includes at least a negative lens and a positive lens and the first sub-unit includes at least a negative lens and a positive lens. The third lens unit includes at least two lens components having a positive refractive power, and the following conditional expressions (1) and (2) are satisfied: 61??d1G_max_p??(1), and ?0.03?Tp2Ga_min_p?0.0165??(2).

Abstract: A variable magnification optical system includes, sequentially from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit, and a fifth lens unit having a positive refractive power, and each of the lens units makes a different movement relatively to a lens unit that is adjacently positioned at least at one of a time of changing magnification, a time of focusing, and a time of image stabilization.

Abstract: The zoom lens has an aperture stop arranged between the second lens unit and the fourth lens unit. During zooming from the wide angle end to the telephoto end, the distances between the lens units vary in such a way that the distance between the first lens unit and the second lens unit is larger at the telephoto end than at the wide angle end, the distance between the second lens unit and the third lens unit is smaller at the telephoto end than at the wide angle end, and the distance between the fourth lens unit and the fifth lens unit is larger at the telephoto end than at the wide angle end. The zoom lens satisfies the following conditional expression (1): 3.5?LTLw/IHt?8.9??(1).

Abstract: A variable magnification optical system includes: in order from an object side, a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and an image-side lens unit. The image-side lens unit includes a lens belonging to a first region and a lens belonging to a second region. At a time of changing magnification, the second lens unit and the third lens unit move.

Abstract: An image forming optical system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a rear-side lens unit which is disposed nearest to an image. The rear-side lens unit includes a positive lens and a negative lens. The first lens unit and the third lens unit do not move in an optical axis direction. At a time of focusing, the fourth lens unit moves toward the image side. The third lens unit includes a positive lens and a negative lens. A motion blur correction lens unit is disposed in the third lens unit, and the following conditional expressions (1) and (2) are satisfied: 0.59?|fMF/fMB|?3.0??(1) 70.0??dFFp??(2).

Abstract: An image forming lens system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit. The first lens unit includes a front-side lens unit having a positive refractive power and a rear-side lens unit in order from the object side. The second lens unit moves at a time of focusing. The third lens unit includes a positive lens element. Each lens element in the front-side lens unit is a lens element that satisfies following Conditional Expression (a). The rear-side lens unit includes a negative lens element and a positive lens element. The front-side lens unit includes a diffractive lens component having a diffractive lens surface. The diffractive lens component has a positive refractive power. Following Conditional Expression (1) is satisfied: ?0.7?f/fLens??(a) 0.015??GFGR/f?0.25??(1).

Abstract: A zoom optical system includes a front-side lens unit, an intermediate lens unit, and a rear-side lens unit. The front-side lens unit includes a first front unit and a second front unit, and a distance between the first front unit and the second front unit is wider at a telephoto end than at a wide angle end. The intermediate lens unit includes a first intermediate unit and a second intermediate unit, and a distance between the first intermediate unit and the second intermediate unit is narrower at the telephoto end than at the wide angle end. A distance between the second intermediate unit and a lens unit adjacent to the second intermediate unit varies. The second intermediate unit moves at the time of focusing, and the following conditional expressions (1) and (2) are satisfied: 0.9?LTLT/LTLW?1.17??(1) 4.2?KMBT?20.0??(2).

Abstract: A telephoto lens includes first, second and third lens units. The first lens unit has positive refractive power front-side lens, first rear-side lens, second rear-side lens units, and one of a plurality of negative lens elements satisfying 0.5?|f/fLn|?4.908. The third lens unit has positive and negative lens elements. The first rear-side lens unit includes a predetermined negative lens element. Lens elements of the front-side lens unit include at least one positive lens element. The first and second rear-side lens units have predetermined negative and positive lens elements, and a positive lens element respectively. Conditional Expression 0.247??GFGR1/f?0.5 is satisfied. f and fLn are focal lengths of the telephoto lens and predetermined negative lens element. ?GFGR1 is an axial air space from an object-side surface in the front-side lens unit to similar surface in the first rear-side lens unit.

Abstract: A zoom optical system includes a plurality of lens units, the plurality of lens units consist of lens units having a positive refractive power and lens units having a negative refractive power, and the lens units having a positive refractive power include a positive lens unit and an image-side positive lens unit, the image-side positive lens unit is not moved, in the lens plurality of units, a space between the lens units disposed adjacently is changed at a time of zooming, at a time of focusing, or at a time of zooming and at a time of focusing, the positive lens unit includes a predetermined positive lens satisfying the following Conditional Expression (2), and the following Conditional Expression (1) is satisfied: 0.1?fGBUN1/fGPM?2.1??(1), and 60.8??dGPMP1?100.0??(2).

Abstract: An image forming lens system includes an aperture stop, and an image-side lens unit group which is disposed on an image side of the aperture stop. The image-side lens unit group includes a first image-side lens unit having a negative refractive power, a second image-side lens unit having a positive refractive power, and a third image-side lens unit having a negative refractive power. Any one of the first image-side lens unit, the second image side lens unit, and the third image-side lens unit is a focusing lens unit which moves along the optical axis at the time of focusing, and the following conditional expression (1) is satisfied: 0.06<|ffo/f|<0.4 ??(1) where, f denotes a focal length of the image forming lens system at the time of focusing at an object at infinity, and ffo denotes a focal length of the focusing lens unit.

Abstract: A telephoto lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit, and the first lens unit includes a front-side lens unit having a positive refractive power and a rear-side lens unit, and the second lens unit moves at the time of focusing, and the third lens unit has a positive lens and a negative lens, and the front-side lens unit includes lenses positioned closer to the object side than a predetermined negative lens that satisfies Conditional Expression (a), and the rear-side lens unit has the predetermined negative lens and a positive lens, and Conditional Expressions (1A) and (14) are satisfied: 0.5?|f/fLn|??(a), 0.015?DGFGR/f?0.25??(1A), and 0.19?DGFairmax/DGF?1.0??(14).

Abstract: An image forming lens system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit. The first lens unit includes in order from the object side, a front-side lens unit having a positive refractive power and a rear-side lens unit. The second lens unit moves at a time of focusing. The third lens unit has a positive lens element. The rear-side lens unit includes a negative lens element and a positive lens element. The front-side lens unit has an aspherical surface having a positive refractive power on an axis, or the rear-side lens unit has an aspherical surface having a negative refractive power on an axis. The lens element closest to the object side in the first lens unit is fixed in position. Following Conditional Expression (9) is satisfied: 0.06?|fG2/f|?0.195??(9).