Convergence and rms errors of temperatures in runs where the number of photon packages n_P is increased by a factor of 200 over the iterations. The final iterations use 18 million photon packages per frequency. Results are shown for different combinations of ALI and reference field methods, as indicated in panel a. For reference, the red curves show the results for the constant n_P of 18 million photon packages per iteration. Markers are drawn for every second iteration.