Left panel: Image of the true sky including point sources and diffuse emission. All images are created at frequency 152 MHz with a minimum and maximum baseline distance of 50λ – 250λ. Middle panel: Diffuse emission with a 4 h track point spread function of LOFAR-HBA applied. Right panel: Residual emission is obtained by subtracting the image created prior to the DI gain calibration from the one created afterward.