1. A single camera with wide-angle optics, such as a fisheye lens or curved mirror;
2. Multiple cameras looking out directly in different directions; or
3. Multiple cameras looking out off flat mirrors, which is FullViews patented approach.
Whereas multiple cameras offer much higher resolution than any single camera, multiple cameras looking out directly are in general incapable of producing seamless, artifact-free and blur-free composite images no matter what, because of parallax. FullView evades parallax through its patented approach in which multiple cameras look out off flat mirrors such that all the cameras are effectively looking out in different directions but from the same single viewpoint. As a result, FullViews composite images, whether a video or still view panorama, and irrespective of their resolution, are always seamless, artifact-free and blur-free, and they provide much higher resolution than outwardly pointing cameras.
The Google Tech talk below by Vic Nalwa, President of FullView, is a must see for anyone interested in panoramic imagery:
See http://www.fullview.com/ for more technical details - pdf link