Patent ID: 8358926

Claim:
An imaging apparatus to which an interchangeable lens unit is mountable, wherein the lens unit has a lens group, a diaphragm, and a stepping motor configured to drive the diaphragm, the stepping motor including a plurality of coils, the imaging apparatus comprising: a control unit configured to control exposure during video photography by changing a diaphragm value, a charge accumulation time or a gain of an imaging element, wherein the control unit controls the stepping motor by exciting the plurality of coils, and switches operation modes in association with the driving of the stepping motor depending on the type of the lens unit; and a determination unit configured to determine whether or not the position of the diaphragm is changed by shutting off a current supplied to the plurality of coils, wherein, in a first operation mode that the driving of the stepping motor is different from a second operation mode, the control unit controls the stop position of the diaphragm based on the output of the determination result obtained by the determination unit, wherein the first operation mode is a mode which uses a phase by which the position of a rotor is not held when a current supplied to the plurality of coils is shut off, and the second operation mode is a mode which uses a phase by which the position of a rotor is held when a current supplied to the plurality of coils is shut off.