Evolution of the average of the dynamic range value of short-exposure images as a function of the standard deviation of the phase piston (or OPD) between interferometer arms. This was numerically obtained through a Monte Carlo statistical approach. Each point is evaluated over 10 000 computed PSF. This curve is computed using the actual test-bench characteristics (apodization coefficients, array configuration, working wavelength, etc.). The only instrumental defect taken into account in this simulation is the piston phase error. For example, the DR_s mean value of 1000 corresponds to a 22 nm OPD standard deviation.