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.bekindtopets.com/super-save-Vetscan-Flex-4-Rapid-Test-25-ct-super-buy/