When it’s in ultra widescreen.
Yesterday I had a meeting with Amazon to talk about their consumer electronics department. They showed off some of the latest gadget goodies they are selling, including a high-definition HD-DVD device playing The Last Samurai on a plasma television. The picture looked pretty good. But after staring at it closely, I realized something: It didn’t show much more detail than a regular DVD.
That wasn’t the fault of the HD-DVD equipment or format, but rather of the TV and of Hollywood. Let me explain why.
You see, the HDTV standard calls for a 16:9 aspect ratio. That’s 16 units of length for every 9 units of height. (So, if the screen were 16 inches wide, it would be nine inches tall. 32 inches wide would be 18 inches tall, etc… They can also be expressed as decimals. For example, 16/9=1.78)
But not all films are shot in 16:9. Many are in a wider 5.5:3 aspect ratio. And big sensations like Samurai are in the 7:3 ratio called Panavision or Cinemascope. To fit the picture into the 16:9 ratio of a typical movie theater screen or HDTV, big chunks of the screen at the top and bottom go blank. (For more on aspect ratios, check this page.)
You’ve probably seen this before, so what’s the big deal? Well, let’s now think about pixels.
HDTV comes in two resolutions: 1920 by 1080 pixels and 1280 by 720 pixels (each a 16:9 ratio). Very few TVs currently offer the 1920 by 1280 resolution. They generally support 1280 by 720, and quite a few provide a slightly higher interim resolution of 1366 by 768, with a little bit of up-scaling to stretch out the 1280 by 720 image.
To see what this means for a DVD, let’s take a typical
plasma TV, the 50-inch Panasonic TH-50PX60U,
with a resolution of 1366 by 768. (Panasonic is the biggest seller of plamsa in the US, and 50-inch TVs are poised to become the most popular size.)
If you happen to be watching a movie shot in 16:9, then you get to use all the screen’s pixels. But what about a movie shot in 5.5:3? It will still fill all 1366 pixels lengthwise, but to maintain the aspect ratio, it can only fill 745 pixels from top to bottom. The definition of HD is at least 720 lines from top to bottom, so that still qualifies.
Now, what about a Panavision/Cinemascope film? To preserve a 7:3 aspect ratio, it can use only 585 screen lines. That is not HD. And in fact, it’s not much better than a regular DVD, which has 480 lines.
The situation gets even worse on lower-resolution HD displays. Projectors, for example, typically provide the exact 1280 by 720 resolution called for in the HD spec. With a 5.5:3 film, that comes out to 698 lines – technically just shy of HD. And a 7:3 film gets just 548 lines.
These problems all go away on a top-end HDTV, with 1920 by 1080 pixels. But these TVs are still rare and pretty expensive.
Now, there are other benefits to high-definition DVDs. They support higher data rates and therefore should have less “compression artifacts” or splotches that result from trying to squeeze so much visual information onto a little disc.
But don’t assume that a DVD looks good just because it says high-def. Amazon also showed off a Samsung device of the Blu-ray high-def flavor, which was playing the movie Hitch. It looked awful. The images were full of static and occasional big splotches from what looked like a sloppy film-to-digital transfer. I can’t tell for sure if it was the particular disc, the Samsung player, or some other factor. But the bottom line is that you can’t yet count on a high-def DVD actually looking good. (Although I have seen some beauties.)
Add to that the fact that we are in the midst of a format war between HD-DVD and Blu-ray, with no end in sight. Plus, these devices are pricey, and content is limited (about 100 films for each format, with a few movies in both.) All that, plus the reduced resolution of widescreen DVDs on most TVs, makes me think, hmmm better let some other suckers buy this early equipment and settle things out before I plop down any of my own money.