An imaging optical system includes lens group Gm located on that is closest to an object among lens groups in which a distance between the lens groups changes during zooming, the lens groups having negative power. Lens group Gm includes, in order from the object side toward an image side, lens element LGmF1 having the negative power, lens element LGmF2 having the negative power, both surfaces of lens element LGmF2 having an aspherical shape, and at least two lens elements having power. The present disclosure provides the imaging optical system having good various aberrations such as spherical aberration, astigmatism, and distortion and an imaging device and a camera system that are provided with the imaging optical system.

An imaging optical system includes lens group Gm located on that is closest to an object among lens groups in which a distance between the lens groups changes during zooming, the lens groups having negative power. Lens group Gm includes, in order from the object side toward an image side, lens element LGmF1 having the negative power, lens element LGmF2 having the negative power, both surfaces of lens element LGmF2 having an aspherical shape, and at least two lens elements having power. The present disclosure provides the imaging optical system having good various aberrations such as spherical aberration, astigmatism, and distortion and an imaging device and a camera system that are provided with the imaging optical system.

An image capturing apparatus that allows a photographer to easily recognize whether or not a blurring generated in an image at the time of image capturing is due to a spherical aberration variable mechanism is provided. The image capturing apparatus, to/from which a lens barrel can be attached/detached, comprising a mounting unit configured to mount the lens barrel, a processor; and a memory storing a program which, when executed by the processor, causes the image capturing apparatus to obtain an adjustment amount of spherical aberration from the lens barrel mounted on the mounting unit, and control a display device to display information about the adjustment amount together with an image obtained through the lens barrel.

A conversion lens attachment structure includes a first magnetic body provided on a conversion lens device that includes a conversion lens, and a second magnetic body provided on a device main body that includes a master lens. The conversion lens device is attached to the device main body due to a first surface of the first magnetic body and a second surface of the second magnetic body being pulled toward each other, and the second magnetic body is provided such that a normal line of the second surface is not parallel to an optical axis of the master lens.

A conversion lens attachment structure includes a first magnetic body provided on a conversion lens device that includes a conversion lens, and a second magnetic body provided on a device main body that includes a master lens. The conversion lens device is attached to the device main body due to a first surface of the first magnetic body and a second surface of the second magnetic body being pulled toward each other, and the second magnetic body is provided such that a normal line of the second surface is not parallel to an optical axis of the master lens.

A camera device includes an optics unit and a sensor unit releasably connectable to each other, and an electronic accessory releasably connectable to the optics unit by means of a threaded fitting associated with a rotation axis, wherein the optics unit comprises optics unit connectors, which in an assembled state of the camera device each is aligned and in contact with an associated electronic accessory connector of the electronic accessory thereby forming an electric connection between the electronic accessory and the sensor unit via the optics unit, wherein the optics unit connectors and the associated electronic accessory connectors form a first group consisting of at least one optics unit connector and associated electronic accessory connector arranged for power transfer and a second group consisting of at least one optics unit connector and associated electronic accessory connector arranged for signal transfer.

A camera device includes an optics unit and a sensor unit releasably connectable to each other, and an electronic accessory releasably connectable to the optics unit by means of a threaded fitting associated with a rotation axis, wherein the optics unit comprises optics unit connectors, which in an assembled state of the camera device each is aligned and in contact with an associated electronic accessory connector of the electronic accessory thereby forming an electric connection between the electronic accessory and the sensor unit via the optics unit, wherein the optics unit connectors and the associated electronic accessory connectors form a first group consisting of at least one optics unit connector and associated electronic accessory connector arranged for power transfer and a second group consisting of at least one optics unit connector and associated electronic accessory connector arranged for signal transfer.

A lens barrel having one end and the other end includes: a first frame that is movable and holds optical members; a second frame that is arranged to be relatively movable toward the other end with respect to the first frame, and holds optical members; and a third frame that is mounted on the first frame so as to be movable, and holds an optical member. The first frame includes a first stopper portion that comes into contact with the third frame to limit movement toward the one end. The first frame includes a second stopper portion that comes into contact with, when the first frame is most distant from the second frame, the third frame to limit movement toward the other end. The second frame includes a third stopper portion that has a contact surface located close to the one end with respect to the second stopper portion, and that comes into contact with, when the second frame is located within a range on the optical axis where the third frame is movable, the third frame to limit movement toward the other end.

A lens barrel having one end and the other end includes: a first frame that is movable and holds optical members; a second frame that is arranged to be relatively movable toward the other end with respect to the first frame, and holds optical members; and a third frame that is mounted on the first frame so as to be movable, and holds an optical member. The first frame includes a first stopper portion that comes into contact with the third frame to limit movement toward the one end. The first frame includes a second stopper portion that comes into contact with, when the first frame is most distant from the second frame, the third frame to limit movement toward the other end. The second frame includes a third stopper portion that has a contact surface located close to the one end with respect to the second stopper portion, and that comes into contact with, when the second frame is located within a range on the optical axis where the third frame is movable, the third frame to limit movement toward the other end.

An image capturing apparatus includes a first mount portion and a first cylindrical member that has a color different from a color of the first mount portion and is disposed in a circumferential direction of the first mount portion, an accessory includes an exterior portion, a second mount portion, and a second cylindrical member having a color different from a color of the second mount portion and similar to a color of the first cylindrical member and disposed in a circumferential direction of the second mount portion, and in a state where the accessory is attached to the image capturing apparatus, reference surfaces of the first mount portion and the second mount portion are in contact with each other, and the first cylindrical member and the second cylindrical member are externally exposed regardless of whether the accessory is attached to or detached from the image capturing apparatus.