Provided is an imaging element in which a first frame rate is a frame rate higher than a second frame rate, and a first processor is configured to read out image data of a plurality of frames in parallel within an output period of image data of one frame defined by the second frame rate, acquire a focus driving speed and a rolling shift amount, decide a combining condition for the image data of the plurality of frames stored in a memory based on the acquired focus driving speed and the rolling shift amount, perform combining processing on the image data of the plurality of frames in accordance with the decided combining condition, and output the image data after combining obtained by the combining processing.