This paper presents a method of autocalibrating a stereo system using the full parameterization of the fundamental matrix. The technique is an improvement of classical autocalibration methods that use corresponding points and it is aimed to reduce the number of processes required to achieve a satisfactory calibration. An analysis of the matching points used in the calibration process is carried out in order to select them based upon their quality or reliability. Using this technique, a significant reduction of the convergence errors in the calibration process is obtained.