Combination of RDI and dark hole techniques. Left: resulting image of HR 4796 circumstellar disk after RDI using the dark hole calibration on the east side for both the target (896 s of integration time) and the reference star (880 s of integration time). Two arrows point toward the areas where the intensity is attenuated by the FQPM coronagraph transitions. Right: 5 σ azimuthal standard deviation as a function of the angular separation from the star. The standard deviation is calculated in the east part of the image (rough position of the dark hole after rotation of frames). The full line is calculated after RDI is used, and the dotted line is calculated before.