Question on Analog vs. Digital Signals for Plasma TV

If there is a better forum for this question please direct me. I currently have a regular RCA 32" television that is hooked up to cable TV via "analog" signal. My question is.... If I buy a plasma TV and stay with analog (not digital) will my picture be an improvement over my older TV just due to different technology??

thanks for any help!

Reply to
buck
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As far as I've seen so far, the simple answer to that is " no ". On some picture content, the image produced by either plasma or LCD is superb. A nice stationary bowl of flowers, or a properly lit studio shot of a newsreader, for instance. But switch channels to the motor racing, and you will be able to count the number steps it takes the car to get across the screen. You'll also wonder why the paint appears to be coming off the body, and trailing along behind ... Ok, perhaps not quite that bad, but nevertheless, you will get clearly visible motion artifacts on a flat panel TV of any type, compared to a CRT set, no matter whether you feed it with a digital or analogue signal. If you are serious about buying a plasma, get the salesman to show you it working on a large variety of content.

The effects are at their worst when you are watching a programme that is originated digitally, broadcast and received digitally, and reproduced on a pixel addressed display. I currently have three different models of LCD set in the workshop, and personally, I wouldn't have any of them in my house as anything other than a second set.

Arfa

Reply to
Arfa Daily

A good explanation follows.........

It's also important to note that a conventional TV set "blurs" the image so that it looks smooth. Since plasma and LCD TV sets have discreet pixels, there is a much more noticable space between them. 42 inch plasma TVs used to be so bad that you could see the spaces between the lines at over a foot away. Hopefully you won't sit so close to the set, but you get my point.

Digital signals are the worse offenders, the analog signal is broken up into discrete pixels before being recorderd or transmitted. This has nothing to do with the connection method of your TV set, DVDs, and anything that is encrypted (digital cable, satellite TV, etc) all are digital and have a specific number of pixels.

When you play the signal back on a device with a different number of pixels, some sort of conversion has to take place to map the image from one set of pixels to the other. Converting the signal to analog and back again has its charm, it will give you a smoother looking picture.

For example, an LCD TV may have a resolution of 1280 pixels across. Now if you have a usual DVD, it has the image chopped up into 720 pixels across. If you display the picture properly, one pixel on the screen to one pixel in the image, you will see black bars on the sides. DVDs are usualy 520 pixels high, so a TV with 1280x1024 resolution will "adjust" the horizontal and just display every vertical pixel twice. This may look odd, but the human brain can compenstate.

If you get a "widescreen" TV with a horizontal resolution of around 1440 pixels, then a DVD playes quite nicely by doubling every pixel. This may require a digital input to the TV because of the high frequency range (bandwidth) required to carry so many pixels.

The problem with plasma and LCD TVs is the manufacuring of the display. There is no such thing as a color display, they are really combinations of three single colors, called primary colors, red, green and blue. You brain sees combinations of these colors as the entire range of color, but it is not really there. Each pixel requires three real pixels one of each color on the display.

Therefore a single 1024 line of pixels is really 3,072 pixels, with 1024 groups of three. This is difficult to produce in high resolution. OLED (organing light emiting diode) technology will replace this. OLEDs still have discrete pixels, but the process of putting them on a screen is similar to an inkjet printer. While a three inch 800x600 pixel LCD screen is almost impossible to manufacture a 800x600 OLED screen is relativly easy and cheap.

Since computer processing power is also easy to come by and cheap, in a few years, a high resolution OLED TV will be availble at a price far lower than a plasma, DLP or LED screen which will automaticly convert almost any picture into one that looks good and it will be fast enough to show motion without artifacts.

Of course, the first OLED TVs will cost around $10,000 but in 20 years you will see them on cereal boxes.

Living in Isreal brings me an interesting point of view, the TV standard is PAL, but most of the programs on satellite and cable TV are from the U.S. in NTSC. NTSC signals have a faster frame rate (30 versus 25), but a lower resolution (525 lines versus 625). Obviously these have to be mathematicly converted to fit the taller screens and less frames per second. The quality of the conversion varies and you see all sorts "problems" with the picture.

DVDs are not a problem, almost everyone here who has a DVD player has a multisystem TV set (PAL tuner, NTSC or PAL via the video in) and the DVD players switch frame rates automaticly. "Zone free" players are the norm here, if they were only zone 2 no one would buy them.

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM
IL Voice: (07)-7424-1667  IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
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Reply to
Geoffrey S. Mendelson

LCD displays all suffer from lag like you are describing, whether the source is digital or analog. This is not the case with PDPs. Digital signals that are overcompressed may look pixelated on a PDP, but display lag is a far greater problem with LCD. What one will find with any new set with digital processing is that much of the analog cable will look worse on the new set than it did on an older analog crt. There are two reasons for this. One is that the newer set likely has higher resolution and will reveal the limitations in the original material. The other is that many systems do a poor job of upconverting the signal to higher display rates. This latter problem involves both inadequate filtering of the analog signal before conversion, and unsophisticated upsampling schemes in the digital.

The solution is simply to watch the material that you plan to view on the set before buying it. Products vary greatly within and between manufacturers and technologies.

Leonard

Reply to
Leonard Caillouet

Hey..... Thanks to everyone for some great comments. Now I am totally unsure about whether to get a plasma or not.... :~) I will take your advice to see different content at the store before I make final decision. What to do? What to do?

-thanks again!

Reply to
buck

Since you are in the U.S. (I assume), I would go to Sam's club and buy the cheapest widescreen TV with an S-Video in jack and the cheapest DVD player with an S-VIDEO out.

Get a membership in the cheapest DVD rental place you can find and if you can get CBS and FOX with an antenna, the cheapest antenna that will let you do this.

Relax, watch the content matched to the TV and consider in two years, you spent about half a dollar a day on entertainment. After two years things will be so different that you will probably want to get rid of what you have anyway.

Higher resolution over the air digital TV is coming. Digital is available in most places in the U.S., but the resolution will improve, DVDs will be replaced with something better and large screen TVs will be cheaper. OLED one inch screen video players are out now, large screen ones can't be too far behind.

On the other hand if you have $5000 to impress your friends with, or have a large disposable income and no life, you can get a DLP TV set, a DBS satellite dish and a progresive scan DVD player and see the state of the art video.

In two years when the bulb goes in you DLP TV, you will find that it's all obsolete anyway. :-(

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM
IL Voice: (07)-7424-1667  IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
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Reply to
Geoffrey S. Mendelson

The answer can be complicated or simple. As for your old analog set, the Plasma or LCD will have a much nicer picture. The technology of the new sets are far ahead of the older sets. But, if you don't feed them the proper signal in the proper mode, they will not work to the optimum.

The new displays work best in their native mode. This has to do with that they are using pixel addressing rather than a more simple scanning of the image. If the signal sent to the LCD or Plasma screen is not in the native mode, the system has to do some complicated interpolation to be able to display the picture. The image will then look softer.

There will be a time that everyone who wants to watch TV will have to be up to date. Most likely over the next 10 years, analog broadcast TV will be no longer in service.

As for the new TV display technology, it is true that there are some bugs with it. This is especially so, with rapid moving objects. As time goes on, the manufactures are finding ways to make these sets have higher contrast ratios, and have faster response times. There are some newer LCD monitors out there now that are faster than the older CRT ones. The prices are still very high for a very good monitor, but these will come down.

Eventually the stores will no longer be selling CRT type monitors. Most of the manufactures have stopped making the picture tubes, and are not interested in selling CRT type monitors, or TV sets.

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JANA
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Reply to
JANA

I'd love to agree with you on all that, but most of the stores that I do work for, which sell flat screens - both LCD and plasma, won't place them side by side with CRT sets, because these show up the flat panels for what they are - generally inferior.

With a good signal going in, a CRT set looks good under all circumstances, from a full dark night-time shot, to a brightly lit studio shot - and if we're talking digital here, then let's say a high bitrate source such as QVC. On the contrary, flat panel sets of either variety will struggle to handle this high dynamic range of brightness and contrast with anything like the same fidelity as a CRT, no matter what fancy tweaking software and hardware has been incorporated.

And motion artifacts, and shading artifacts *are* a problem with these displays. Some displays are signally better at reducing the 'unwanteds', than others. If I was really intent on buying myself one, and had the money, then I would definitely buy a Pioneer plasma.

As far as the technology getting better is concerned, I'm not so sure about that. About 5 years ago, I was called in by a colleague to sort an audio problem with an installation of multiple large plasmas in a bar. They were NEC professional types, and I will admit to the picture on them being excellent. But then it should have been at over 6 grand UKP apiece ...

I'm not sure what actually represents an LCD monitor that's *faster* than a CRT one. I guess that you must be talking about refresh rates, because the response times of CRT phosphors are very very short, and I'm pretty sure that there is not the LCD panel made, that can come close to them in pure pixel on/off response time, but I could be wrong on that one.

I do absolutely agree with you on them looking best in native mode, though. However, "best" is the operative word here ...

I know a few people who have bought both LCD and plasma displays, and ultimately been less than satisfied by them. But, by the same token, I also know people who have bought them and been absolutely delighted. I think it is a case of those people being the same ones that you used to call on for a CRT set fault, and when you got there, the picture was bright green. Then the customer walks in the room and says " It's the sound that I've got a problem with, mate ! "

I'm sure that there's still lots of life in this thread yet !! I guess that the poor old OP is now well confused, but he's at least got the idea now that he needs to look at plenty of content typical to what he watches before making a decision. Oh, and don't be fooled by those fancy Sony demo rooms, with a top of the range model, shown in the dark ... d;~}

Arfa

Reply to
Arfa Daily

JANA...... Thanks for answering my original question. I knew there would a debate on which technology is better too. I have learned some things.

Reply to
buck

Arfa..... thanks.... All good stuff from you.

Reply to
buck

The new LCD TV technology provides a better reception and a much clearer picture via analog or digital. Take a peek at our free guide to LCD TV's or Feel free to view our popular direct from the manufacturer Flat Panel LCD TV's and Flat Panel LCD PC Monitors.

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PMBBAY

Reply to
admin

I work around these tvs where i work ( salvage outfit ) its my job to see if all the stuff works before its sold . I notice the plasma & lcd sets are getting better in the last 2 years . I have a 36`` sharp lcd and like it better than the old tube set . I did notice some lag at first but soon after dont notice it anymore and dont care I also got used to the stretching at the sides & just dont notice that anymore either .

Reply to
Ken G.

No problem. As a slight aside, I was in one of the stores that I do work for today, and I was discussing this thread with the owner, and I was saying that about the only plasma that I would possibly entertain, would be the Pioneer. I was very surprised when he said that the Daewoo series 3 models use Pioneer drive electronics, with a Samsung screen. The only bit that Daewoo make themselves, is the analogue tuner board. He went on to say that in his opinion, the picture produced by this set actually equalled that of a CRT, and was better even than the Pioneer itself, and was the first he had seen that he could actually say this about.

That left me a bit non-plussed, I have to say, because from a professional repairer's point of view, I've always considered Daewoo gear to be pretty poor stuff, from their cars to their HiFi's, but I'm gonna have to look into this, because this guy is a reliable source of opinion, and not an hysterical " believer ".

Another thing that he said, that set me thinking. He has himself, at home, got a plasma TV. The only reason that he has it is because he came by it as a refused-quote repair. Once he had fixed it up, he took it home, and replaced his regular TV with it. Now he tells me, that he spent the next month agonising over whether to keep it, or just put it back up for sale, as in his opinion, the picture was crap. However, over that month, he says that he got used to it, and not having another CRT set in the house to compare it to, started to ignore its shortcomings. He has now had it for over a year, and he says that although the picture is still crap, for all of the reasons that we've been discussing here, he no longer notices, and loves it.

So there you go. Just maybe, you need to go for the best looker that you can afford, put it in, and get used to it ...

Arfa

Reply to
Arfa Daily

I currently

Easy answer. With basic analogue signals, your RCA (or any properly operating quality TV) will have a better, more detailed picture than any digital technology TV. Digital TVs just aren't designed to convert analogue 24 fps to digital.

But on true HD sources, HD TVs (plasma, LCD, DLP, CRT, whatever) look spectacular. However, these true HD channels are but a small percentage of what most people receive and watch. I have several customers who have already worn out a plasma without ever seeing a decent picture on it.

Reply to
John-Del

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