Single-band residual images produced via bandpass selfcal with different solution intervals for B_p: 30 min (upper left), 15 min (upper right), 7.5 min (lower left), and with the 7.5 min solution smoothed using splines (lower right). Even in the best-case image, the dominant source 3C 147 was not subtracted out perfectly, leaving behind DR-limiting artefacts.