In 1936, the BBC introduced its viewers to high-definition TV. (Well, that's what they called it, anyway.) The Beeb's new broadcast system produced a blurry, black-and-white 405-line image. Still, it was a lot better than the 30-line standard it replaced. Seventy years later, the name's the same; only the specs are different. High-definition TV has morphed into a color system with up to 1,080 scanning lines. But just as Americans are beginning to embrace the new HDTV era, the definition of high definition is changing once again.
The Japanese national broadcaster NHK, which created the first modern HDTV system in the 1970s, is working on that system's successor, Ultra High Definition TV. Its resolution will be so high it'll make your new big-screen plasma look about as sharp as the 1950s Sylvania HaloLight in your grandparents' attic. But don't fret - NHK doesn't expect Ultra HD to hit the market until around 2025.
The new system will offer 16 times the resolution of today's HD, which maxes out at 1,920 pixels of horizontal resolution and 1,080 pixels of vertical resolution (pixel columns by pixel rows); Ultra HD will have a whopping 7,680-pixel horizontal resolution by 4,320-pixel vertical resolution. NHK also plans to use 22.2-channel surround sound, with ten speakers at mid-height, nine above your head, and three at your feet. Bullets won't just whiz by - they'll practically brush up against your nose. Great stuff - if you're watching TV on a display the size of the DiamondVision screen at Yankee Stadium, that is. NHK is demo'ing Ultra HD on 440-inch (36.7-foot) screens - which makes sense, because watching it on a regular-size set would have about as much impact as viewing an HDTV program on a cellphone.
Nobody knows yet how Ultra HD's monstrous amount of data can ever be sent over cable, satellite, or the airwaves. And the technology NHK is working with is relatively primitive. To display the images at demos, it needs to use two projectors; the image size is so large that one alone can't create a bright-enough picture. And uncompressed Ultra HD files are enormous. The video is recorded at 24 gigabits per second, compared to 1.5 for standard HDTV. The hard drives used to store the data weigh 600 pounds, and 18 minutes of video requires 3.5 terabytes of space. But the work NHK engineers are putting into it shows that no technology ever remains static.
When HDTV became available here in 1998, Joe Flaherty, a CBS engineer instrumental in its development, famously said that "today's HDTV images are the worst HDTV we'll ever see." And he was right. As technology improves, HDTV just keeps getting better. But any display is only as good as the material available to show on it. To improve the picture quality of both DVD and the new HD DVD and Blu-ray formats, as well as movies seen on cable or satellite, the movie industry is using a technique called oversampling. By creating digital masters at twice the resolution of HDTV and then downconverting them, technicians can preserve all the content found on the original 35mm film.