(a), (b) Phase reconstructions of the resolution chart sample as obtained from data taken with a photon flux of photons s−1 and the STCS and with a photon flux of photons s−1 and no STCS, data sets 1 and 2, respectively. In both cases the sample was scanned over a rectangular area as indicated by magenta lines. Fits of the error function to the edges of the line scans (dashed red lines) yield line-spread functions with FWHM values of 23 nm and 26 nm, in (a) and (b), respectively. (c), (d) Calculated two-dimensional power spectral densities (PSDs) of the reconstructed phases depicted in (a) and (b), respectively. Frequencies corresponding to a real-space pixel size of 10 nm and 7 nm are indicated as magenta circles. (e), (f) PSDs and phase retrieval transfer functions (PRTFs) from both data sets after azimuthal averaging. Data set 1 is represented in blue whereas data set 2 is represented in red. The arrows in (f) indicate the PRTF cutoff at about 0.5 yielding a half-period resolution of 12 nm and 25 nm for data sets 1 and 2, respectively. Frequencies corresponding to real-space pixel sizes of 50 nm and 10 nm are further emphasized in (e) and (f) by vertical lines. Scale bars denote 1 µm in (a) and (b).