In geometric calibration of stereoscopic cameras the object is to determine a set of parameters which describe the mapping from 3D reference coordinates to 2D image coordinates, and indicate the geometric relationships between the cameras. While various methods for stereo cameras with ordinary lenses can be found from the literature, stereoscopic vision with extremely wide angle lenses has been much less discussed. Spherical stereoscopic vision is more and more convenient in computer vision applications. However, its use for 3D measurement purposes is limited by the lack of an accurate, general, and easy-to-use calibration procedure. Hence, we present a geometric model for spherical stereoscopic vision equipped by extremely wide angle lenses. Then, a corresponding generic mathematical model is built. Method for calibration the parameters of the mathematical model is proposed. This paper shows practical results from the calibration of two high quality panomorph lenses mounted on cameras with 2048x1536 resolutions. Here, the stereoscopic vision system is flexible, the position and orientation of the cameras can be adjusted randomly. The calibration results include interior orientation, exterior orientation and the geometric relationships between the two cameras. The achieved level of calibration accuracy is very satisfying.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.