A camera body is provided, to which an interchangeable lens is mountable, the interchangeable lens including a diaphragm and capable of sending driving speed information of the diaphragm. The camera body has a receiving unit operable to receive the driving speed information of the diaphragm from the interchangeable lens, an imaging unit operable to capture a subject image formed by the interchangeable lens to generate image data, a controller operable to set an imaging condition for the imaging unit, and a sending unit operable to send a control signal for changing brightness information of the interchangeable lens to the interchangeable lens. The controller sets the imaging condition for a period from a start to an end of a driving of the diaphragm according to the received driving speed information of the diaphragm when the sending unit sends the control signal to the interchangeable lens.