Variances of the iMZ phase estimators (in rad², logarithmic scale) as a function of N the number of photons per pixel per frame available for measurement for the λ/D pinhole diameter and 40/60 beam splitter. The expressions of the estimators are given in Eqs. (12) and (14). The solid lines plot the theoretical variances, given in Eqs. (30) and (31), for the joint (in blue), symmetric (in green), and asymmetric (in orange) MLEs of the phase. The dashed lines correspond to the simulated results for a null input phase.