HDTV's fall in to one of several catagories: Tube, CRT-RP, Plasma, LCD, LCP-RP, DLP-RP, and the new exotics.

Tubes are just like the sets we know and love. They have a giant picture tube in them. The tube makes them very heavy and they don't usually come in sizes > about 40". You can burn in pictures but it's generally very difficult.

CRT-RP's are what people usually think of when they think of big Tv's. They have three small CRT's in them and use a mirror to project the image on to the screen from behind (the -RP stands for Rear Projection.) The sets are HUGE and weigh a TON. They burn in "easily." They are also amoung the most inexpensive of large screen sets.

Plasmas are flat and don't generally burn in easily. True HD plasma in large sizes is still very expesive: more than DLP-RP and lots more than CRT-RP.

LCD's are flat like plasma but are, at heart, digital. They have pixels, not weirdo strange analog plasma gas. LCD panels are expensive to manufacture in large sizes. They can't burn in.

LCD-RP. What if you have a small (~9"), high quality LCD and then used a mirror to project the image on to the back of a screen just lke CRT-RP does? Then you'd have LCD-RP. Like LCD, it can't burn in. They are light (~100# for a 50") and are 'tabletop' sets. Not really wall mountable like plasma or LCD, but not huge hulking sets like CRT-RP. More like the size of a traditional tube set. They are more expensive than a CRT-RP but less than a DLP-RP or Plasma. Like LCD it is a digital set with the concept of pixels. I own a 50" Panasonic LCD-RP; for me it hit the sweet spot between price and quality.

DLP-RP uses a ball with thousands of individually controlled mirrors to produce a picture. Sounds wacky but works VERY well. It uses a mirror to project the image on to the back of a screen (all RP's do this, hence the term Rear Projection. ;) It can't burn in. It's digital. It costs more than a LCD-RP and less than a Plasma. Tabletop just like LCD-RP. I tried like hell to buy one of these; they were very backordered, so I got a 50" LCD-RP for about $1000 less than the 50" DLP-RP I wanted.

ExoticS: D-ILA, LCOS, etc: Very similiar to LCD-RP and DLP-RP in that they are digital, don't burn in and are tabletop setsl. The first and sewcond generations are just coming out so I'm not sure I would completely trust these yet.

In terms of picture quality, CRT-RP (adjusted) is best, followed by the exotics, plasma, LCD, DLP-RP, LCD-RP (non-adjusted). LCD-RP may be the worst but that's relative in the HDTV field: if you're not a videophile then you probabally won't notice. If you like to watch HDTV and DVDs you are not a videophile, you're a normal person. If you have $200,000 home theater you're a videophile (why are you reading this?) CRT-RP is the best when properally adjusted. Proper adjustment is something you can't do yourself, you have to call in a specialst. It costs at least $500 and you have to have it redone every 6 months. If you don't do that then you have a non-adjusted set and a picture quality that's worse than LCD-RP. In short: don't worry about picture quality. You'll like them all. be careful when looking at these sets in stores. The salespeople in most stores don't set them up so they don't look tht great. 10 minutes of setup gets you a lot of improvement. Some stores will adjust the sets that cost a lot and 'degrade' the settings of the cheap sets to stear you towards the expensive ones. Don't fall for it. Most new/current model sets look very good these days.

Burn-In
CRT-RP is the worse, followed by Plasma and Tube. The exotics, LCD, LCD-RP and DLP-RP can't burn in. Their technology doesn't allow for it. Don't believe that "sets are better these days' stuff. They are better, but they still burn in. Do you want to stretch out all of your 4:3 content to 16:9 (yech!) all the time? Do you want to only play video games for 1-hour at a time? Do you want to not watch ESPN, CNN, and other stations that have 'bugs' and scrollers at the bottom of the screen? Do you want to live in paranoia for the rest of your Tv's life? Do you want your Tv to tell you how to watch it? I don't, so I got a set that can't burn in. I like to turn on my XBOX and hit pause, then I go on a 3 day vacation just to spite the CRT-RP owners. Don't buy a Tv that will burn in: it's a waste of money unless you have enough money to buy a replacement every few years or if you're ONLY going to use it to watch movies in your home theater room.

Digital/Analog
We live in an age of wonder: the digital era. I don't think most people realize how disruptive (in a good way) digital is. Analog loses quality as soon as it leaves the source. In analog you have to worry about interferance. The signal at the destination is never what you sent, it's only the best thing given the loss and interferance it encountered. It's fuzzy, blurry, and wishy-washy. A $10,000 piece of electronics is really better than a $300 piece because it has less interferance. Digital is different. What you send is EXACTLY what you get. You either get the 0/1 or you don't. A digital set (Digital is different than HDTV. Digital is LCD, DLP-RP, LCD-RP, some exotics. NOT PLASMA) can take advantage of that by doing something called '1-to-1 pixel mapping.' What is sent by your DVD player/HDTV box is EXACTLY what is displayed on your set. Every pixel on the source is displayed EXACTLY the same way on your set. To do this you need more than a digital set. You need a digital source (DVD player, HDTV set top box from your Sat or cable provider.) The digital source needs to have a DVI or HDMI output. These are DIGITAL ouputs. All of the other output, component, composite, s-video, those are all ANALOG. Your Tv will need a digital input, DVI or HDMI. Finally, your Tv needs to actually be digital: it needs to understand and display nativly the concept of a pixel: LCD, LCD-RP, DLP-RP, and some exotics. Taken together you get EXACTLY what the source is, the best possible picture. (Even in my eyes, a layman, I can easily tell the difference in an all digital system and one that's not. It really is that much better.) If you have an analog signal, or an analog cable or your set is analog (Tube, CRT-RP, Plasma, some exotics) or you don't have DVI/MDI inputs or outputs, then you can never have 1-1 pixel mapping and you're picture will be less than perfect. It will still look good, but. why settle for less than perfection?

LCD-RP, DLP-RP and some exotics have an interesting 'drawback': they have a consumable. Eventually there is a part in the set that will have to be replaced: a special light-bulb inside the set will eventually grow dim and burn out. These little (uh, medium size, actually) buggers cost about $300. You will need to replace it every 3-5 years. My Tv is on from 6am to midnight every day (not counting my 3-day 'pause the xbox' weekends. ;), 18 hours a day. I'll need to replace the bulb in a little less than 3 years. I'm ok with that.

Digital sets have a drawback: there is space between the pixels. For example: Think of a pixel as a circle. Bunch the pixels up as close as can in a box ,one at each corner. Right in the middle will be some black space that no pixel touches. Repeat a lot (say, the size of a typical 50" HDTV screen) and you get something known as the screen-door effect (SDE). Imagine you are lookng through a screen door. You can see through it (the pixels) but you also see the black grid lines ot the screen (the space between the pixels.) If you sit close (~2-3 feet) to a digital set you will see the SDE. If you sit farther back you will not see it. Analog doesn't have this problem since there's no space to speak of between the scan lines. Image you drew a straight line with an extra-sharp pencil. Draw another one 1 cm under it. You could see the paper between the lines pretty clearly. Now image you did the same thing with a fat ragged marker. The ragged edges and dye would cause the lines to bleed in to each other. The color may be lighter in the center, but it won't be like the pencil. BTW: Most people agree you should sit about 8-9 feet away from an HDTV set, so this shouldn't be an issue in any case. I usually sit 3-4 feet away when XBOXing, and I don't notice it. I see it sometimes about 3-4 feet away when I'm watching 'normal' analog Tv.

Once last thing, all Tv's are plagued by viewing angles. All technology gets dimmer when you're off angle horozontially (remember the old LCD computer monitors) and/or vertically. For the best picture you need to be in front of the Tv (maybe off horozontal axis about 30 degrees) with the center of the Tv at your eye level. Higher, lower, or off to the side the picture will get dimmer. The height issues can be solved by basing your Tv stand purchase so it puts the Tv at eye level when you're on the couch/bed/floor (whereever you expcet to view it more.) When looking at Tv's in stores I would suggest you move around a btit and see how the picture brightens/dims as you move off to the sides and above/below eye level. That will help you see how it will fit in to your room, and there's little the sales driods can do setting-wise, posative or negative, to change that factor.
If I were purchasing today I'd get a 50" LCD-RP or DLP-RP with at least 1 DVI and/or HDMI input. That should run between $2500 and $3500.

Thanks gcbrowni for the info! original post is here, so a page find on "09-17-2004, 08:23 PM" and you'll skip right to his post.

Looks like I'm gonna get a DLP eh. I wonder where 3-LCD comes into play?