I’ve heard some radio commercials for satellite tv companies that say that if you buy a big wide-screen tv and have cable, the picture’s not going to be very good. They say that the wide screen tvs force the cable signal to “spread out” across the whole screen, making the picture worse than it was with your old, non-wide screen tv. They say the solution is to get their satellite service, which sends a digital signal, and covers the whole screen without any distortion.
Anyone ever experience this? Is it even true? My first reaction is that it’s not true for digital cable, just analog cable. Am I right about that part?
It depends on the settings of your TV. If the TV is set to display everything in widescreen mode (16:9 aspect ratio) then a standard TV picture (4:3) then it will “stretch out” the picture to fit. Most widescreen TV’s can be set to display the picture in 4:3 mode with black bars on the sides.
This isn’t exactly what I meant (or at least how I understood the commercial). The commercial made it sound like the cable signal isn’t meant to be shown on a large screen- forget I mentioned wide-screen, I took it to mean it happens with any big screen tv: that the signal is meant to be shown on a screen of a certain size, and to show it on larger screen somehow dilutes the picture, so to speak, and the picture isn’t as good as it would be with the digital satellite picture.
Widescreen (16:9) TVs can usually be set to any of several different display modes, like:
‘stretch’ the picture to fit the screen (distorts 4:3 signals, correct for 16:9 signals)
fit to width of screen (lops off the top and bottom of 4:3 signals, but the screen is completely filled without stretching)
fit to height of screen (black or gray bars on right and left of 4:3 signals)
I know a lot of widescreen TV owners either don’t know this, don’t care about it, or hate the vertical bars, though, because a lot of people just put up with the stretched-out picture. Drives me nuts.
In this context, what they are saying is that the larger the screen the more that the “imperfections” are visible. If you have a marginal picture to start with, and make it bigger, it will appear more grainy and imperfect. They’re trying to tell you that their signal is so clear and crisp it will appear flawless on the big screen. Maybe so, but unless your cable signal is really poor, it should be just fine. I’m not saying that an analog signal is every bit as good as digital, because it isn’t, but a good quality analog signal should do just fine on a big screen TV.
Well, as you increase the picture size, reception problems do become more noticeable. A signal that is mediocre-but-watchable on a 9" portable TV might be an unwatchably fuzzy, scintillating, distracting mess on a 50" screen. But that’s not a new phenomenon with HDTVs or wide-screen TVs - it’s always been the case. Since the early days of photography, I’d dare say.
Even with digital cable or satellite TV, there’s only so much information in the picture. It’ll still start looking ugly if you magnify it enough.
And frankly, I doubt there’s much difference in the distortion of analog cable and digital cable (or satellite) at large screen sizes, as long as you’re feeding it into the TV’s analog input. The signal coming out of your cable/satellite decoder is an analog NTSC signal, just like the one coming out of the wall for analog cable, and it has the same 480 line vertical resolution. Blowing a 480 line picture up to 40" is going to make it just as fuzzy no matter where it came from.
Actually, there is a formula for determining the optimum screen size for a given resolution and viewing distance. That’s why if you sit too close to a big-screen TV you start to see scan lines and other flaws, and you instinctively want to sit back.
Most living rooms are designed for a TV of about 32" displaying a broadcast signal. If you put a giant TV in the room, you’ll feel like you’re sitting too close unless you move back. However, the better TVs have a ‘line doubler’ built into them which helps increase the apparent resolution, making you want to sit close again.
HDTV has the opposite problem. If you buy an HDTV of the same size as your current TV and watch from the same distance, you won’t get the benefit of the HDTV resolution. Your eyes won’t be able to resolve the added detail. So you want to sit closer. A 30" HDTV has an optimum viewing distance for most people of only 3 feet or so. Think about the distance you’re sitting from your computer monitor - an HDTV has a roughly equivalent resolution. So you’d want to sit about that far from it when watching movies.
So for an HDTV to work in a normal living room, it has to be very large. That’s why the HDTV market is dominated by very big screens - 55" rear projection units, front projectors with 8 ft wide theater screens, etc.
I think HDTV will wind up in two fragmented markets - desktop units that will double as computer monitors, and very big screens. I don’t see a big market for those 32" HDTV units.
Well, you can get HDTV on cable too. I don’t subscribe to it myself, but Comcast digital cable has HDTV versions of CBS, ABC, ESPN, HBO, and Showtime here.