i had my tv professionally calibrated.
with the zoom... just look at maybe the science channel, tbshd... one of the newer added channels. you can tell the channel is zoomed in on because the text at the bottom of the screen saying someone's name or info or whatever is hanging halfway off the screen, or credits are not scrolling properly or whatever. also you can see that some shots are just not right. the tops of people's heads are hanging out of the shot or someone that should be in the shot is half way out to the side.