An imaging apparatus is provided with a control unit, a noise reduction processing unit and a pixel value calculation unit. The control unit controls pulse widths of horizontal synchronization signals outputted to an imaging device such that a feed-through period and a signal period, in a case in which pixel addition in the horizontal direction is performed at the imaging device and imaging signals are outputted, are longer than a feed-through period and a signal period, in a case in which pixel addition in the horizontal direction is not performed at the imaging device. The noise reduction processing unit executes noise reduction processing to reduce the effects of noise produced in the imaging signals. The pixel value calculation unit calculates a pixel value on the basis of a first signal sampled in the feed-through period and a second signal sampled in the signal period.