The present invention relates to a virtual sport system for acquiring a good image of a ball by controlling a camera according to the surrounding brightness. One embodiment of the present invention provides a virtual sport system which comprises a photographing unit, having a camera for acquiring an image of a ball, and a simulator, for calculating the physical quantity of the ball on the basis of the image of the ball; and which further comprises a control unit that extracts image information from at least one image acquired by the photographing unit by means of the camera, and determining, on the basis of the image information, a control signal for adjusting the image gain or the exposure time of the camera.