Locality of the photometric and astrometric precision tested with the Hessian minimization. Artificial planets are injected in the M′ filter data at a range of separations and position angles. The absolute offsets between the injected and retrieved value of the position (left panel) and the contrast (right panel) are shown on a logarithmic color scale for each tested position. The white solid line is the mean offset (top axis) as a function of separation (left axis). The standard deviation of the offset across the position angles is indicated by the white shaded area. The white cross denotes the position of β Pic b, which was removed beforehand.