Figure 3.

Moiré fringe contrast at 60 kVp/43 keV mean energy, with the 5.4 μm m=3 interferometer at normal incidence (a), and at 18° incidence (b). c) Moiré contrast with the 10 μm period m=1 interferometer at 80 kVp/58 keV mean energy and 10° incidence. The Moiré images are normalized (‘flat-fielded’) to background images obtained with the phase grating rotated at 90° (i.e. without phase effects); the images are plotted on an intensity scale from 0.5 to 1.5.