Comparison between the direction-independent calibrated images and those we expect from direction-dependent calibration. The right panel shows a high-resolution, high-fidelity, approximately thermal noise limited image that was created using the facet calibration method. The left panel represents the same region in our direction-independent calibrated images. The colour scales on both images is between −3 and 10 times the noise where the direction-independent calibrated image noise is 360 μJy/beam and the facet calibrated image noise is 100 μJy/beam. The green circles show the positions of sources detected at seven times the noise in the direction-independent LOFAR image. The larger black circles and blue squares indicate entries in the TGSS and FIRST catalogues, respectively.