What the hell? YouTube is now supporting video resolution that's high enough to satisfy those persnickety cinematographers who shoot digital cinema? That resolution is called 4K, and at 4,096 x 3,072 pixels, it's way higher than the sharpest Blu-ray discs. But don't get too excited. Resolution isn't the only benchmark of quality, as a quick glance at these 4K files from YouTube will reveal.