Global calibration methods for multi-camera system are critical to the accuracy of vision measurement. Proposed in this paper is such a method based on several groups of sphere targets and a precision auxiliary camera. Each camera to be calibrated observes a group of spheres (at least three). while the auxiliary camera observes all the spheres. https://www.duospiritalis.com/top-deal-Serra-Avatar-Urza-s-Saga-clearance/