The compression used to bring hd into your home, or store HD on a disc, results in poor color separation and large macro blocks and video artifacts. You can see this by standing close 1-2 feet away from your TV. A far cry from a good viewing experience. As you move further away from the tv, these are less noticeable, giving you the perception of Clear viewing. If your glasses are not up to date, you wil notice the effect even less. Thus able to enjoy video where the darker scenes have no noticable noise.