Imaging LOFAR 148 MHz observations of the Cygnus X region. The field of view displayed corresponds to 25% power of the primary beam. Left: deconvolved LOFAR image without short-spacing information. While these data are sensitive to emission on angular scales as large as 96′, negative (un-physical) emission induced by large-scale emission in the Galactic plane is present. Center: frequency-interpolated short-spacing map at 148 MHz (see Sect. 2.1.2) and 72′ resolution. Right: LOFAR data imaged with the short-spacing map as an initial model (see Sect. 2.1.3).