A method and a system for detecting surface defects on electronic circuits, such as Printed Circuit Boards, are described herein. An exposed surface of the optical element is exposed to an ion flux generated by an ion source to remove at least some areas of the surface that have been damaged by exposure to the environment within the vacuum chamber. The additional energy accumulator device and the brake force generator can be designed in such a way that the force required of the brake force generator during a braking operation in order to generate a defined brake application force level that is greater than zero but less than the maximum brake force is zero. The digital camera includes a rear camera. The first and second control portions are operable to select the respective different total volume values according to a presently selected print mode, or a gray-scale value at each picture element of an image to be printed.