SeanTech

When is a High-Def DVD Not Really High Def?

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.

CES - Samsung goes all-out on TV Tech

One thing I really like about Samsung is that it always pushes the boundaries. Sometimes that results in flops, but in general, it's been a great driver of bringing laboratory wizardry into the mainstream. And Samsung is doing a lot of technology pushing with TVs.

In the LCD and plasma world, Samsung is continuing its SUV strategy of building 'em bigger, bigger, bigger. Take the new LN-S8281D -- an LCD television with an absurd 82-inch diagonal measurement. (That's nearly seven feet!) Samsung can create such a monstrosity because it owns one of the biggest LCD glassmaking operations in the world. Is this a real product, or just a stunt? Well, both the availability date and the price are listed as "TBD," although Samsung says it will come out sometime in 2006. When it does, it will likely be crazy expensive. But in 3 years, who knows, maybe lots of people will have somewhat affordable LCD TVs of gigantic proportions (though perhaps not quite 82 inches). Really, this is a job for a projector, not a flat panel. But flat-panels look far more impressive in newspaper photos.

If you can't wait for the LCD, Samsung pledges to have by February a plasma TV of a not-too-shabby 80-inch diagonal. (No price announced yet.) They say this will be the largest "consumer" TV -- in contrast to an even-bigger "just for show" plasma they displayed at last year's CES. One legitimately cool thing about this TV is that it supports the highest HD resolution: 1920 by 1080 pixels (or about two megapixels, if you will). Called "1080p" by those in the know, this resolution is the hot new item in TVs.

Samsung (along with all the other major TV makers) is rolling out a bunch of 1080p models -- some of them in sizes that actually make sense. For example, Samsung will start selling in June a 46-inch 1080p LCD model for $10,000 (will probably be half that price in a year).

Even bigger, and a lot cheaper, is a new 1080p rear-projection model, the HL-S5679W, a 71-inch model that will sell for $4,999. But especially cool about this TV is the use of a virtually brand-new projection technology. Instead of a mercury arc lamp bulb (as found in almost all projectors), this TV uses light-emitting diodes. LEDs produce fantastic color, but until now they haven’t been bright enough (at a reasonable price) to power a projector. So I'm a little skeptical. Rear-projection TVs already have brightness problems (they only put out enough light to look good if viewed from head-on. They are useless if viewed from the side.)

The really cool thing about LEDs is that they can produce better color. Traditional projectors pass white light through color filters to produce so-so shades of the red, green, and blue primary colors. Filters also, of course, absorb a lot of light that never makes it to the screen. LEDs actually glow in the colors red, green, and blue - and potentially far richer versions than you get from filters. So this TV has the potential to produce fantastic color. We'll see.

CES - Optoma Promises Colorful HDTV Theater on the Cheap

This one sounds great -- almost too good to believe. The folks at Optoma just announced a high definition projector, the HD72, that they say will sell for under $2000. And it's not just any old projector -- it's equipped with a new technology from Texas Instruments that might actually produce better color.

Some people mistakenly get excited about projectors as a cheap way to get HDTV. That isn't really true. Yes, a good projector can cast an image of around 100 inches diagonal (bigger than any flat panel on the market). But it isn't necessarily cheap. The really low-cost projectors (between $1000 and $2000) are usually not high-def. They have instead the resolution of DVDs -- with 480 picture lines of detail. (And they usually don't produce enough light for those 100-inch images. More like 60-80 inches.) Until recently, stepping up to high-def (starting at 720 lines) usually required jumping up to at least $3000 - and that was for the bad projectors. The good ones cost at least $5000.

Now, Optoma happens to make pretty good projectors -- at least the ones I've seen. So I'm cautiously optimistic about their ability to pull off a good HD model for $2,000.

And I'm really curious to see the colors from it. The new projection technology, called BrilliantColor - - forms images by combining six hues: red, green, blue, cyan, magenta, and yellow. (Most TVs just use red, green, and blue.) According to TI, the extra colors will help in producing some shades that traditional TVS don't capture so well -- like the sky at sunset.

By my reckoning, this is only the second TV to sue BrilliantColor. The first was the Mitsubishi HC300U that I wrote about on December 2. For more about that projector -- and a lot more about the six-color technology -- see my old post.