An x-ray system including an x-ray source, a detector having an input area, a monitor configured to display detected images, means for determining a location of a Region of Interest (ROI) of a patient on the displayed image and a collimator having means for projecting the region of interest (ROI) on a selected fraction of the input area exposed by the x-ray source, the collimator movable in a plane parallel to the detector input area, the collimator includes a plurality of holes having different sizes, each one of the holes configured for projecting the selected fraction of the exposed area for a different zoom of the detector.
