In this preliminary study, we utilized the Webcam with bigger field of view (FOV) in order to overcome existing limitations of conventional navigation stereo cameras with small FOV thereby improving marker detection capacity. In results, we demonstrated that FOVs of conventional camera and the Webcam were 885 mm and 1,685 mm, respectively which indicates better FOV of the Webcam. Consequently, the stereo camera using the Webcam provided sufficient FOV and expanded the effective range of marker detection thereby enabling discrimination of patient heads and transducers as well as tracking in any direction.