A medical viewing system comprises an X-ray source, a collimator for limiting the X-ray radiation output of the X-ray source and a flat X-ray detector, wherein the collimator is adjustable such that the subsequent X-ray images acquired by the X-ray detector comprise a rectangular shape with variably rounded corners. The acquired X-ray images have a shape, which is in-between a circular shape and a rectangular or square shape. Acquired images with this shape may then be displayed on a display unit, wherein the borders or the images are distant from the borders of the designated screen area of the display unit in order to define a gap on the display. On rotation of an acquired image the rounded corners move towards the borders of the screen and are dimensioned such that they never cross the borders of the display. The used area of the screen 30 is approximately 30% larger than that of a circular image, e.g. taken by means of an image intensifier.
