A tool positioning system for performing a medical procedure on a patient includes an articulating probe having a distal portion and a stereoscopic imaging assembly for providing an image of a target location. The stereoscopic imaging assembly comprises: a first camera assembly comprising a first lens and a first sensor, wherein the first camera assembly is constructed and arranged to provide a first magnification of the target location； and a second camera assembly comprising a second lens and a second sensor, wherein the second camera assembly is constructed and arranged to provide a second magnification of the target location. In some embodiments, the second magnification is greater than the first magnification.
