LoTSS mosaics showing the W3/W4/HB3 star forming region (left) and the Cygnus loop supernova remnant at an angular resolution of 6″. The mosaics have sensitivities of approximately 120 μJy beam⁻¹ and the emission, which is deconvolved, from each of these Galactic regions spans over 12 million 1.5″ × 1.5″ pixels. The calibration of these complex regions was done with a modified version of the pipeline used for LoTSS-DR2 which provided more stability whilst still allowing us to calibrate in 45 different directions for each individual pointing that makes up these mosaics (see Sect. 5.2 for details).