<Li> As the distance of the object increases, the image asymptotically approaches the focal point </Li> <Li> In the limit where S approaches infinity, the image size approaches zero as the image approaches F </Li> <P> Most curved mirrors have a spherical profile . These are the simplest to make, and it is the best shape for general - purpose use . Spherical mirrors, however, suffer from spherical aberration--parallel rays reflected from such mirrors do not focus to a single point . For parallel rays, such as those coming from a very distant object, a parabolic reflector can do a better job . Such a mirror can focus incoming parallel rays to a much smaller spot than a spherical mirror can . A toroidal reflector is a form of parabolic reflector which has a different focal distance depending on the angle of the mirror . </P> <P> The Gaussian mirror equation, also known as the mirror and lens equation, relates the object distance d o (\ displaystyle d_ (\ mathrm (o))) and image distance d i (\ displaystyle d_ (\ mathrm (i))) to the focal length f (\ displaystyle f): </P>

What effect does the curvature of a mirror