A camera generates a first video having visibility lower than a predetermined visibility suitable for a process using a video in a video output apparatus, encodes the generated first video, and transmits the encoded first video, and an adjustment instruction including a parameter for adjusting the visibility of the first video to be equivalent to the predetermined visibility, to the video output apparatus. The video output apparatus acquires the first video and the adjustment instruction, transmitted from the camera, adjusts the visibility of the first video to be equivalent to the predetermined visibility by using the parameter, based on the adjustment instruction, and outputs the adjusted video to an output unit.