The paper deals with the coherent and incoherent production of Fourier images. Modelling experiments on obtaining Fourier images in total incoherent radiation of the visible range have carried out. The results of the experimental observation of Fourier images of two‐dimensional periodic objects in the range of ultra‐soft X‐ray radiation are reported. An undulator at 2.5 nm wavelength was used as a coherent X‐ray radiation source. Diffraction images up to order 16 of the Fourier‐plane with a minimum line width 0.2 μm have been obtained.