The NCP image after multi-directional calibration and source subtraction using SAGECal. After a shallow deconvolution using CASA (mainly to estimate the PSF), the skymodel is restored onto the image. The circle indicates an area of diameter 10 degrees. The image has 12   000 × 12   000 pixels of size 4′′ with a PSF of 12′′ and the noise level is about 100 μJy/PSF. Due to the fact that RS and CS beam shapes have different FOVs the sources at the edge of the image are distorted. In addition, due to frequency smearing, the sources at the edge of the image appear “attracted” towards the center. The colourbar units are in Jy/PSF.