An image sensor configured to function, according to setting information, as a synchronous master that controls synchronous imaging performed by a plurality of different image sensors each functioning as a synchronous slave, or to function as a synchronous slave , the image sensor comprises: an imaging unit configured to perform imaging and output an image via a data bus; and a control unit , wherein, when the sensor is set to function as the synchronous master , the control unit is configured to control imaging performed by the imaging unit , and imaging performed by each of the different image sensors , wherein the control unit uses: a generation circuit configured to generate a synchronous signal (Vsync) for controlling the imaging unit ; a retention circuit configured to retain an acquisition state of a stop request; and a mask circuit configured to selectively output, in accordance with the stop request acquisition state of the retention circuit , the synchronous signal (Vsync) generated by the generation circuit as a synchronous slave synchronous signal (Vsync_out) to the different image sensors functioning as synchronous slaves that perform imaging under control by the synchronous master, and wherein, in a case where a stop request is acquired, the control unit is configured, by using the retention circuit and the mask circuit , to stop output to the different image sensors of the synchronous slave synchronous signal. an imaging unit configured to perform imaging and output an image via a data bus; and a control unit , wherein, when the sensor is set to function as the synchronous master , the control unit is configured to control imaging performed by the imaging unit , and imaging performed by each of the different image sensors , wherein the control unit uses: a generation circuit configured to generate a synchronous signal (Vsync) for controlling the imaging unit ; a retention circuit configured to retain an acquisition state of a stop request; and a mask circuit configured to selectively output, in accordance with the stop request acquisition state of the retention circuit , the synchronous signal (Vsync) generated by the generation circuit as a synchronous slave synchronous signal (Vsync_out) to the different image sensors functioning as synchronous slaves that perform imaging under control by the synchronous master, and wherein, in a case where a stop request is acquired, the control unit is configured, by using the retention circuit and the mask circuit , to stop output to the different image sensors of the synchronous slave synchronous signal. a generation circuit configured to generate a synchronous signal (Vsync) for controlling the imaging unit ; a retention circuit configured to retain an acquisition state of a stop request; and a mask circuit configured to selectively output, in accordance with the stop request acquisition state of the retention circuit , the synchronous signal (Vsync) generated by the generation circuit as a synchronous slave synchronous signal (Vsync_out) to the different image sensors functioning as synchronous slaves that perform imaging under control by the synchronous master, and wherein, in a case where a stop request is acquired, the control unit is configured, by using the retention circuit and the mask circuit , to stop output to the different image sensors of the synchronous slave synchronous signal. <EOS>