X ray near field holography : beyond idealized assumptions of the probe All images are flawed no matter how good your lenses mirrors etc. are. Especially in the hard X ray regime it is challenging to manufacture high quality optics due to the weak interaction of multi keV photons with matter. This is a tremendous challenge for obtaining high resolution quantitative X ray microscopy images. In recent years lensless phase contrast imaging has become an alternative to classical absorption based imaging methods. Without any optics the image is formed only by the free space propagation of the wave field. The actual image has to be formed posteriori by numerical ...