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 July 1, 2005 Widescreen TVs Relate Poorly to Movies’ ShapesAn acquaintance recently complained to me that, although high-definition television is (sometimes) broadcast with an aspect ratio of 16:9 rather than the regular 4:3, he’d noticed that most movies still have black bands above and below the picture. So how does the new screen format relate to the aspect ratios of actual movies? Not very well, I’m afraid. While programs produced specifically for HDTV are often shot in 16:9 (or 1.78:1), and thus fit the screen perfectly, almost no theatrical films are that shape. Many North American movies are shot in 1.85:1, which is called the Academy Standard, but few are released that way. Transferred to 70mm film, for example, they wind up as 2.05:1, and anamorphic processes such as Panavision result in a ratio of 2.35:1. In the latter case, more than half the total screen area is black when the movie is watched on a normal television. The chief advantage of the widescreen sets is that the black bands at top and bottom are smaller than with conventional 4:3 screens. My friend is also confused by the fact that a normal television signal is made up of 525 lines, yet so many of the better non-HDTV sets claim resolution of 700 or 800 lines, and often more. He wonders about the purpose of the extra lines. They’re different lines. The 525 is the number of scanning lines used to "paint" a TV picture from top to bottom of the screen. This number is fixed for a standard NTSC picture, although it includes some lines that don’t actually carry picture information. That leaves about 480 lines, and in the new terminology of digital television, that’s how a regular TV picture is specified. The high numbers refer to horizontal resolution, a measure of the amount of fine detail a set can produce in the horizontal direction. It’s a function of the bandwidth a set can handle, and the higher the number, the better. There is a point of diminishing returns, however, because no conventional television signal contains many more than 500 lines. As with many specs, resolution numbers are partly a numbers game and partly a testament to the engineering quality that has gone into the equipment. Fortunately, as actual high-definition TV becomes more and more common, such considerations will become increasingly academic. Then there’s the problem of setting up a video display for best results. Several setup DVDs are available that will enable you to accurately set up a conventional NTSC monitor (so far, all DVDs produce 480i signals), but even without one of those, you can approximate the proper settings and materially improve your set’s picture quality. The first thing to realize is that almost all sets come from the factory with their brightness and contrast settings cranked way too high. This can make for a striking picture in a dealer’s showroom, but one that’s far from accurate. And a too-bright picture tends to "bloom" somewhat, reducing horizontal resolution. Before you proceed to other adjustments, therefore, it’s usually a good idea to back off on the brightness and contrast, to the point where they seem too dark, and then live with them that way for a few days to get used to the picture. You might want to reduce the lighting in your viewing room as well. Once you’ve done that, you can begin to adjust the color controls. The best way is to find a station that broadcasts color bars before or after its regular programs, and use that to make the adjustments. The two things to look for are blossoming of the red bar (turn down the color level) and inaccurate yellow (adjust the tint until it’s a pure canary yellow, not orange or green). After that, check the skin tones of a good live broadcast; local news is usually excellent for that. If your set lets you do it, store your settings in memory so you can return to them if somebody fiddles with the controls in your absence. ...Ian G. Masters
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