CCD images of the focal spot obtained after X-rays passed through the lens in Fig. 4, as registered by the YAG crystal/CCD system. Three images on the left for three different θ angle values are shown, out of more than 25 collected. Two false-color images are shown on the right for clarity (for 0 mdeg and 4 mdeg). The sketches show the definition of the angle θ. The elements of the drawings are not to scale. X-rays propagate into the page.