Schematic of the primary X-ray optical components in the experimental setup. The KB focusing system is placed at a distance of zU = 87.7 m away from the undulator source (U). After passing a monochromator (not shown here) and before impinging onto the mirrors, the beam is confined by a system of hybrid metal single-crystal slits (S1H/S1V) in the horizontal and vertical directions. A further metal slit system (S2H) is used for additional horizontal collimation, immediately downstream of the slit pair S1. The KB system consists of a vertically (MV) and horizontally (MH) focusing mirror with a fixed elliptical shape and a common focal plane at focal distances of fV = 302 mm and fH = 200 mm, respectively. Non-focused or partly focused parts of the incoming beam are blocked by a large pinhole (P1, diameter = 1 mm) immediately downstream of the KB system. A second pinhole (P2) is placed a few millimeters (zP2) upstream of the focal plane, into which the sample (S), a Siemens star test pattern, is placed. The two-dimensional detector (D), a Pilatus 300K (Dectris), is placed at a distance of zD = 5.49 m from the sample. On-axis optical microscopes (not shown) are placed both between P1 and P2 as well as downstream of the sample for visual feedback of the sample area.