Abstract: A zoom lens includes, in order from an object side, a first lens group G1 having a positive focal length, a second lens group G2 having a negative focal length, a third lens group G3 including an aperture stop S and having a positive focal length, a fourth lens group G4 having a negative focal length, and a rear side lens group G5. The first lens group includes a negative lens and a positive lens disposed in order from a most object side. The first lens group and the third lens group are fixed in power varying from a wide angle end to a telephoto end. The second lens group moves from the object side to an image side in the power varying. The zoom lens satisfies following conditional expressions (1) and (2). 2.1?F1/Fw?3.0 ??(1) ?1.2?F3/F2??0.

Abstract: A zoom lens having a large magnification ratio, small F-number change at zooming, and excellently corrected various aberrations, and an image pickup apparatus including the zoom lens are provided. The zoom lens includes a common optical system. The common optical system includes, sequentially from an object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power. In the common optical system, all intervals between each pair of adjacent lens groups change at zooming, and a distance between the fifth lens group G5 and an image plane is constant.

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: An image pickup apparatus includes: a first memory configured to store, as a reference value, angular velocities when the image pickup apparatus is in a rest state relative to ground; a second memory configured to store spin-induced angular velocities; a subtraction circuit configured to subtract the reference value from each of the angular velocities detected for each rotational direction by the angular velocity sensor; a circuit configured to calculate an image stabilization amount for counteracting blur of the object image based on a result of the subtraction or the spin-induced angular velocities stored in the second memory in accordance with an operation mode of the image pickup apparatus; and a drive control circuit configured to drive an image pickup device and a part of the optical system, based on the image stabilization amount.

Abstract: An image pickup system includes an input/output modeling section 24, the input/output modeling section 24 creating, as a population, an image group obtained when a specific target is photographed, (access image), and generating an inference model by using, as teacher data, sequential images selected from the image group created as the population, based on whether the specific target can be accessed, wherein each image of the image group is associated with date and time information and/or position information, and the input/output modeling section 24 generates an inference model for determining based on the date and time information and/or the position information whether a process to the specific target is good or bad.