In this paper, the robustness of a new visual servoing scheme with respect to camera calibration errors is analyzed. This scheme, called 2D~1/2 visual servoing, is based on the estimation of the partial camera displacement from the current to the desired camera poses at each iteration of the control law. Visual features and data extracted from the partial displacement allow us to design a decoupled control law controlling the six camera d.o.f. The necessary and sufficient conditions for local asymptotic stability in presence of camera calibration errors are easily obtained. Then, thanks to the simple structure of the system, sufficient conditions for global asymptotic stability are proposed. Finally, experimental results show the validity of our approach and its robustness not only with respect to camera calibration errors but also to robot calibration errors.