Either by pressing the v.format remote button, or going to HDTV setup, format, you can change the "format". Choices are: 480i 480p 720p 1080i. So what does this do? Does it remap any format to what you select. If so, then why doesn't it just default to what is broadcast? When I change the setting, the picture goes away for a second and you can see a degraded picture at the lower settings.
Where is the best setting to leave it?