Disclosed herein is a dynamic aperture driving apparatus for adjusting the amount of light of a projection optical system and a method of controlling the same. The system includes a rotation means, a driving means, a first detection means and a first detection means. The rotation means is connected at the upper end thereof to the dynamic aperture to be rotated to the right and left within a range of rotating angles. The driving means rotates the rotation means to the right and left according to a predetermined electric signal. The first detection means detects the position of the rotation means using a Hall effect. The second detection means detects the operational error of the first detection means due to variation in temperature.