An image pickup apparatus includes an image sensor, a lens, and an electric module disposed outside the lens when viewed in a first direction. The electric module includes a first inductor, a first transformer, a second inductor, and a second transformer. A second terminal of the first inductor is connected to a third terminal of the first primary winding. A fifth terminal of the second inductor is connected to a seventh terminal of the second primary winding. The first inductor is wound clockwise from a first terminal toward the second terminal. The second inductor is wound counterclockwise from a sixth terminal toward the fifth terminal. The first primary winding is wound counterclockwise from the third terminal toward a fourth terminal. The second primary winding is wound clockwise from the seventh terminal toward the eighth terminal.

A lens barrel has a dial operation member that adjusts an optical function of an imaging optical system, a restriction operation member having a first inclined surface inclined with respect to a movement direction from a release position toward a restriction position, and a cam member provided between the restriction operation member and the dial operation member and having a second inclined surface. In a case where the restriction operation member is moved to the release position, the dial operation member is put into a release state. In a case where the restriction operation member is in the restriction position, the cam member puts the dial operation member into a restriction state.

An accessory mount can be inserted through the camera body mount without any of the first through third tabs being hindered by any of three camera body-side tabs at the camera body mount, as long as the accessory mount is inserted into the camera body mount at a correct interlock phase. The first, second, and third tabs extend over varying lengths along the circumferential direction. The first tab extends over a greatest length and the third tab extends over a smallest length, along the circumferential direction. The accessory mount includes a restricting member, a fitting portion, and a lock pin hole. The restricting member is disposed at a position assumed on a side substantially opposite from the lock pin hole across the fitting portion.

An accessory mount can be inserted through the camera body mount without any of the first through third tabs being hindered by any of three camera body-side tabs at the camera body mount, as long as the accessory mount is inserted into the camera body mount at a correct interlock phase. The first, second, and third tabs extend over varying lengths along the circumferential direction. The first tab extends over a greatest length and the third tab extends over a smallest length, along the circumferential direction. The accessory mount includes a restricting member, a fitting portion, and a lock pin hole. The restricting member is disposed at a position assumed on a side substantially opposite from the lock pin hole across the fitting portion.

In a state in which a position sensor for focusing is viewed in the direction of an optical axis, a line connecting the position sensor for focusing to the optical axis is set as a first reference line and a line orthogonal to the first reference line and passing through the optical axis is set as a second reference line. The position sensor for focusing is disposed in a first region of the first region and a second region partitioned by the second reference line. An X-direction VCM and a Y-direction VCM are arranged in the second region. The influence of magnetism from the X-direction VCM and the Y-direction VCM on the position sensor for focusing is suppressed.

In a state in which a position sensor for focusing is viewed in the direction of an optical axis, a line connecting the position sensor for focusing to the optical axis is set as a first reference line and a line orthogonal to the first reference line and passing through the optical axis is set as a second reference line. The position sensor for focusing is disposed in a first region of the first region and a second region partitioned by the second reference line. An X-direction VCM and a Y-direction VCM are arranged in the second region. The influence of magnetism from the X-direction VCM and the Y-direction VCM on the position sensor for focusing is suppressed.

An accessory that can be attached to a camera body, the camera body including a first camera-side clock terminal that outputs a first clock signal, a first camera-side data terminal that outputs a first data signal, and a third camera-side data terminal to which a third data signal is input, the accessory includes: an eighth terminal that is brought into contact with the first camera-side clock terminal; a seventh terminal that is brought into contact with the first camera-side data terminal; and a ninth terminal that is brought into contact with the third camera-side data terminal, wherein the eighth terminal is positioned between the seventh terminal and the ninth terminal.

An accessory that can be attached to a camera body, the camera body including a first camera-side clock terminal that outputs a first clock signal, a first camera-side data terminal that outputs a first data signal, and a third camera-side data terminal to which a third data signal is input, the accessory includes: an eighth terminal that is brought into contact with the first camera-side clock terminal; a seventh terminal that is brought into contact with the first camera-side data terminal; and a ninth terminal that is brought into contact with the third camera-side data terminal, wherein the eighth terminal is positioned between the seventh terminal and the ninth terminal.

An accessory includes: a detection terminal; a first power supply terminal through which a first power supply voltage is supplied; a first ground terminal used as a ground potential; a second power supply terminal through which a second power supply voltage is supplied; a second ground terminal used as a ground potential; a ready terminal used to indicate whether or not communication is allowed; a first data terminal that receives a first data signal; a second data terminal that outputs a second data signal; a clock terminal that outputs a clock signal; and a third data terminal that outputs a third data signal, wherein: the first ground terminal, the second power supply terminal, and the second ground terminal are positioned between the first power supply terminal and the ready terminal; and the first data terminal and the second data terminal are positioned between the ready terminal and the clock terminal.

An accessory includes: a detection terminal; a first power supply terminal through which a first power supply voltage is supplied; a first ground terminal used as a ground potential; a second power supply terminal through which a second power supply voltage is supplied; a second ground terminal used as a ground potential; a ready terminal used to indicate whether or not communication is allowed; a first data terminal that receives a first data signal; a second data terminal that outputs a second data signal; a clock terminal that outputs a clock signal; and a third data terminal that outputs a third data signal, wherein: the first ground terminal, the second power supply terminal, and the second ground terminal are positioned between the first power supply terminal and the ready terminal; and the first data terminal and the second data terminal are positioned between the ready terminal and the clock terminal.