Residual as a function of major loop iteration for Cygnus A. Here, we compare traditional CLEAN with CG-CLEAN in two different flavors for the minor loop. First row: Cotton–Schwab major cycles with MS-CLEAN in the minor loop. Second row: Cotton–Schwab major cycles with Asp-CLEAN in the minor loop. Third row: CG-CLEAN with MS-CLEAN in the minor loop. Fourth row: CG-CLEAN with Asp-CLEAN in the minor loop.