All images are inherently flawed, particularly in the hard X-ray regime, where manufacturing high-quality optics poses significant challenges due to the weak interaction of multi-keV photons with matter. This complicates the acquisition of high-resolution quantitative X-ray microscopy images. Recently, lensless phase contrast imaging has emerged as an alternative to traditional absorption-based methods, utilizing the free space propagation of wave fields to form images that require numerical reconstruction. Advanced phasing techniques allow for the recovery of complex-valued specimens from single or multiple intensity measurements, although ideal imaging conditions are rarely achievable. This thesis focuses on understanding and addressing the non-ideal imaging conditions affecting X-ray near-field holographic (NFH) imaging, where issues arise from the illuminating wave field or probe, which often deviates from the assumptions of fully coherent and monochromatic radiation. The thesis compiles key findings, including a method for reconstructing the probe of an X-ray nano-focus setup through varied Fresnel number measurements. It also explores reconstruction efficiency in lensless imaging and extends the probe reconstruction scheme to account for partial coherence effects, ultimately aiming to describe the probe's coherence properties. Additionally, it proposes a reconstruction scheme for achieving single-shot recovery of probe a
