A zoom lens system for providing high quality images with higher resolution includes a first lens group (110), an aperture stop (120), and a second lens group (130). The first lens group has a positive or negative refractive power, and includes at least two lens elements having a negative refractive power and at least on lens element having a positive refractive power. The second lens group has a positive refractive power. A distance between a first and second lens group is not fixed.

A plurality of lens units of a zoom lens according to an aspect of the embodiments includes a first lens unit having a negative refractive power, and a rear lens group which includes one or more lens units and has a positive refractive power as a whole. The first lens unit consists of a first negative lens, a second negative lens, and a positive lens which are disposed in order from an object side to an image side. A specific gravity of the first negative lens, a focal length of the second negative lens, and a focal length of the first lens unit are appropriately determined.

A camera head is provided that includes a first lens group, including at least one deformable lens with variable curvature, a second lens group moveable relative to the first lens group, and an image sensor for capturing a light beam received from an endoscope, wherein the first lens group is fixed relative to the image sensor and the aperture of the first lens group is smaller than the aperture of the second lens group. A method is also provided for capturing of an image utilizing a zoom system including a variable power first lens group and a movable second lens group.

An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions,
ndLZ+(0.01425??dLZ)<2.12, and
?dLZ<35.0,
where ndLZ: a refractive index of the lens with reference to d-line, and ?dLZ: Abbe number of the lens with reference to d-line.

An optical system according to the present invention is an optical system consisting of a front lens group having a positive or negative refractive power, an aperture stop, and a rear lens group having a positive or negative refractive power that are placed in order from an object side to an image side. In the optical system, relationships between a distance on an optical axis between a negative lens having the strongest refractive power in the rear lens group and a positive lens placed on the image side of the negative lens, an opening angle of the positive lens, a back focus of the optical system, and a focal length of the optical system are appropriately determined.

Binoculars and an ocular lens have an excellent optical performance. Binoculars include: a first lens-barrel and a second lens-barrel having an objective lens and an ocular lens; and an Abbe-Koenig prism which is an erecting optical element included in the first lens-barrel and the second lens-barrel, and is characterized in that the product of an effective diameter (mm) of the objective lens and the real field of view () is 450 mm or larger.

Pop-out lens systems for compact digital cameras, comprising an image sensor and a lens with a field of view FOV>60 deg and having i lens elements L1-Li starting with L1 from an object side toward an image side, each lens element Li having a respective focal length f.sub.i, the lens elements divided into two lens groups G1 and G2 separated by a big gap (BG), the lens having a pop-out total track length TTL<20 mm in a pop-out state and a collapsed total track length c-TTL in a collapsed state, wherein BG>0.25?TTL, wherein either G1 can move relative to G2 and to the image sensor for focusing or G1 and G2 can move together relative to the image sensor for focusing, and wherein a ratio c-TTL/TTL<0.7.

A magnification-variable optical system having a small size, a wide angle of view, and high optical performance, an optical apparatus including the magnification-variable optical system, and a method for manufacturing the magnification-variable optical system are provided. A magnification-variable optical system ZL used for an optical apparatus such as a camera 1 includes a first lens group G1 having a negative refractive power and including at least two lenses, and a rear group GR including at least one lens group disposed on an image side of the first lens group G1, and is configured so that a distance between lens groups adjacent to each other changes at magnification change and a condition expressed by predetermined condition expressions is satisfied.

Provided is the image pickup apparatus including an optical system forming an image of an object, an image pickup element receiving light from optical system, a driving unit driving at least one of an optical element included in optical system and image pickup element in a direction including a component of a direction perpendicular to an optical axis of optical system, and a determining unit performing first determination that driving unit is set to be in a non-driving state (NDS) or performing second determination that driving unit is set to be in a driving state (DS) based on information regarding object. When first determination is performed, determining unit outputs a signal for maintaining driving unit in NDS or switching driving unit from DS to NDS. When second determination is performed, determining unit outputs a signal for maintaining driving unit in DS or switching driving unit from NDS to DS.

The zoom lens according to the present invention includes, in order from an object side to an image side, a first lens unit with a negative refractive power and a rear lens group including one or more lens units, in which intervals between adjacent ones of the lens units are changed during zooming and focusing. The first lens unit includes three or more negative lenses. The rear lens group includes a focus lens unit with a negative refractive power that moves during focusing. A focal length of the first lens unit, a shortest focal length of the zoom lens, curvature radii of object-side and image-side lens surfaces of a lens in the first lens unit disposed closest to the object side, and a focal length of the focus lens unit are appropriately set.