Left panel shows the RMS noise image of the ELAIS-N1 field, with a contour level at 0.1 mJy beam⁻¹ overlaid. The contours at the positions of bright sources indicate that their direction-dependent effects (DDEs) are not completely eliminated. The right panel depicts the cumulative ratio of pixels in the RMS image against RMS noise values. The x-axis represents the RMS noise value, while the y-axis shows the percentage of image pixels with RMS values greater than or equal to a given RMS noise value, along with its corresponding physical area.