When your TV is sent a 1080i signal, however, a different process occurs: deinterlacing. This is when the TV combines the two fields into frames. If it's done right, the TV repeats each full frame to create 60 "fps" from the original 30.
At 60 frames per second (720p), the camera is getting a full snapshot of what it sees every 60th of a second. With 1080i, on the other hand, it's getting half a snapshot every 60th of a second (1,920x540 every 60th). With most things, this isn't a big deal. Your TV combines the two fields. You see frames. Everything is happy in TV land. 2b1af7f3a8