most (not all, some contributions are QTVR-only due to historical reasons)
many, but depends on photographer's choice of file upload (newer event = more likely to work) and your device's capabilities. You may experience slow playback, distorted images or unexpected browser quitting if there is only limited memory/GPU power available.
Big Ben . . . in the heart of London . . . one of the world's most cherished and often-photographed landmarks. This panorama was taken at 9:33 pm local time on June 23 and even at that hour of the evening the number of sightseers and street traffic was substantial. After observing several traffic light cycles at the intersection of Bridge Street and Victoria Embankment, I realized there would be a brief window of opportunity to shoot a panorama without a tsunami of vehicles and pedestrians moving through the scene, and the masking capability of PTGui Pro took care of the inevitable straggler. The live recording of the Great Clock's chime and strike was made onsite 27 minutes later at 10:00 pm.
Latitude: 51° 30' 2.91" N
Longitude: 0° 7' 26.28" W Elevation: 34 ft.
Precision is: High. Pinpoints the exact spot.