Taking a great leap forward Television: 'Chihuly Over Venice' offers a spectacularly colorful showcase for digital TV on PBS.

November 09, 1998|By David Zurawik | David Zurawik,SUN TELEVISION CRITIC

Digital television arrives tonight on PBS.

While you won't be able to experience it if you don't own a digital set -- and who does? -- several PBS programs this week have information that may help you decide if you want to buy one.

WETA (Channel 26), in Washington, is one of seven PBS stations that will actually start transmitting a digital signal tonight. Maryland Public Television (MPT, Channels 22 and 67) will begin digital broadcasting in 2000.

PBS' first digital showpiece, "Chihuly Over Venice," airs at 9. It looks at a project by glass artist Dale Chihuly to create spectacular chandeliers to hang over the canals of Venice. Viewers without digital television will see the program in letterbox format -- meaning the picture is squeezed down by a black border at the top and bottom of the screen.

The reason is that digital uses the same height-to-width ratio (technical term: aspect ratio) as such feature movie formats as VistaVision. Instead of the 4 units (wide) to 3 units (high) format of the televisions we now use (called analog), digital has a 16 to 9 ratio for width and depth of picture.

It's not hard to understand why "Chihuly" was chosen to launch PBS Digital Week. The cameras follow Chihuly and his team of glass artisans to Finland, Ireland, Mexico and Italy as they team up with other artists to create the spectacular chandeliers. It is 90 minutes of glass being heated, blown, twisted, tortured and caressed into a kaleidoscope of fabulous colors and shapes.

And it is all done against a fantastic travelogue of Venetian canals, Irish meadows, seductive ponds and sea coasts. It's one great visual after another.

I saw "Chihuly" both in digital and analog. The visual difference is considerable, but it alone will not be enough to put a digital television at the top of my list of Things I Will Do With the First Extra $5,000 I Have to Spend.

Not all digital broadcasts will be in the high definition (HDTV) format in which I saw "Chihuly" at the digital TV demonstration suite at MPT. HDTV is the top of the line in terms of visuals offered by digital television.

HDTV's sharp picture and its depth of image makes analog pictures seem flat and watery in comparison. George R. Beneman, who is running the demonstrations at MPT, describes the HDTV picture as similar to what you see through a Viewmaster. He's right, especially in the sense of depth perception among different images.

HDTV also expands the range of colors. As for sound, it is CD quality. All in all, watching HDTV is a lot like seeing a good print of a feature film on a big screen in a movie theater. The difference is large, but it is nothing you have not seen before if you go to movies. In other words, it won't blow your mind.

But there is more to PBS Digital Week and digital television than just brighter pictures and better sound. The clearest explanations of other aspects can be found in "Digital TV: A Cringely Crash Course" airing at 10: 30 tonight on PBS.

The half-hour program features PBS new-technology expert Robert X. Cringely with a little help from such public TV heavyweights as Fred Rogers, filmmaker Ken Burns, chef Julia Child and Steve Thomas of "This Old House."

Cringely and Child use loaves of bread baked in her kitchen to explain a second area of great promise for digital television: multicasting. The idea here is to think of a pipe that links your TV to the transmitter sending a signal. The size (band width) of the analog signal fills the whole pipe. The digital signal is far more compact and will fill only a portion of it, allowing perhaps as many as six digital signals to be transmitted simultaneously. This would allow a broadcaster like MPT or WETA to, in effect, broadcast six channels of different programming simultaneously.

Such digital signals, however, will not be in high definition. The HDTV signal is almost as large as analog, filling most of the pipe. The actual difference in size is yet to be determined. But the idea is that MPT or WETA could go multiple channel during the day and then go to HDTV for prime-time programming.

Thomas helps Cringely explain another area of great promise for digital TV: digitally enhanced broadcasting. The extra space created by the compact digital signal allows a data stream to be fed simultaneously with it to your TV. So, while watching Thomas redo a kitchen on "This Old House," you would be able to download blueprints or cost estimates off the screen.

PBS' first digitally enhanced broadcast will be tomorrow and Wednesday nights at 9 when it airs Burns' documentary on "Frank Lloyd Wright." Expanded visuals and more specific information on various Wright designs are the sorts of data viewers will be able to access.

"In terms of our education and learning mission, the enhanced aspect of digital television is the most exciting one for us," Rob Shuman, the CEO of MPT said last week. "This will allow viewers to use their TV sets more like computers with them programming the TV instead of being programmed by it."

Pub Date: 11/09/98

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