Big TV lust (split)

[ivor]

I have one of those too.  Make sure you get the right gender and put everything on a surge suppressor.  I had to have my TV fixed once already.  Fortunately it was under warranty.

[Sibling Zono (anon1mat0)]

I have a surge suppressor at the wall, a UPS and a power strip (in theory with some surge protection) before the TV, consoles and amplifier (this is lightning happy FL after all).

[Aggie]

Big TV question:  What are the disadvantages of going with a (cheaper) plasma TV instead of LCD? We are apparently in the market for a large TV _{(contrary to popular stereotypes it's the husband here who's reluctant)}  .

I'm not overly concerned about watching anything in HD, if that makes a difference.

[Bob in a quantum-state-of-faith]

Big TV question:  What are the disadvantages of going with a (cheaper) plasma TV instead of LCD? We are apparently in the market for a large TV _{(contrary to popular stereotypes it's the husband here who's reluctant)}  .

I'm not overly concerned about watching anything in HD, if that makes a difference.

Well, I know a tiny bit about that-- I had always assumed plasma was superior-- and it appears initially, this was true.

But LCD has continued with incremental improvements since it's inception in the TV market, whereas plasma is essentially the same as it was.

About 6 months ago, my old vacuum-bottle TV finally died, and I was in the market for a new flat screen.  My criteria:  Name-brand, clear picture, around $500US, HD-width (may as well) and excellent color.  I have off-the-scale color perception, so this was important to me.

I did my initial homework on-line, naturally, and discovered I could purchase locally (my desire) a plasma TV at WalMart (I know-- so beat me up later).   The TV I selected fit the above, and in plasma-- a technology I thought superior (at the time).

I thought it had richer colors, and faster response of pixels.

I was wrong:  the LCD I eventually purchased had the same pixel response-time as the plasma (a fast-moving picture is the only way to test this, such as foot-ball match, or auto racing, where the image is changing rapidly-- you're looking for smearing or pixelating, in a slow-response screen, whereas a fast one does not do this).

And?  The colors in the LCD was superior to the plasma!  That was a surprise to me-- but LCD's have continued to improve as I said-- blacker-blacks, richer colors and so forth.

What made me purchase the LCD over the plasma was this:  the back of the plasma set (in the store-- plenty of open space for ventilation, too) was HOT, HOT HOT.  Almost too hot to touch, in fact!   The LCD, by contrast, was 'baby-fever' warm.   A glance at the amp-rating of each?  I was convinced...the LCD used less electricity, ran cool, had equal pixel-speed and superior color.

Your mileage may vary, with regards to pixel speed and color-- these are brand-dependent.

Bottom line, however is the same:  plasmas run hot, and use more electricity than a same-sized LCD.

[Sibling Zono (anon1mat0)]

Agreeing with Bob I can also tell you that the best image after OLED (for which there are no big screens in the market) is LED backed LCD. Those not only eat even less electricity but are thinner than the average LCD screen. The downside is that those are more expensive.

As for plasma they do have one advantage over most LCDs and its related to Standard Definition TV. Given that you have more pixels in the screen than those in the signal (in plasma you usually get 720 lines) SDTV with 480i needs to be upscaled by the set and the signal is usually analog, any bit of noise in the signal will be more visible. Plasma TVs behave more like CRTs and the bleeding from one pixel to the other smooth out the image while LDCs by not doing so will show more of that noise. The general result is that LCDs have a cleaner image as long as the signal is digital and preferrably HD while plasma's will look better in SD but not as good in HD as an LCD.

[Bob in a quantum-state-of-faith]

Interesting, Zono, I did not know that bit.

As for the OLED's?  I can't wait-- those have even higher efficiencies-- you don't need a separate backlight, unlike LCD's.

The LED-backed LCD's are too new, and these were not available in my area when I was shopping-- or else so exotic the were only on the very highest-end.

I suppose a word about all these letters is in order:

LCD = Liquid Crystal Display*.  These rely on light passing through the device from behind, typically this is a fluorescent or luminescent lamp(s) to either side, with reflective back behind the whole panel, re-directing that output through the display elements.  The color temperature of these lamps is essential to the final color output of the LCD itself.   The individual pixels are colored with a filter, which makes them into whatever color they need to display.  "black" is made by "closing" the pixel itself, and is dependent on the matrix's black color-- originally a serious problem with LCD panels was black appeared more grey-like than black.  Long since fixed in moderate-to-high priced panels.

A point of interest:  90% of the failures for LCD screens (including PC monitors) is the lamp(s) fail, not the display itself.  Replaceing the lamp(s) is not usually designed into the stupid thing-- they want you to just buy a whole'nother set.  Idiots:  it ought to be illegal to design it that way... for the lamp, sooner or later, is *going* to fail.  LCD technology has been around since the 70's and are quite reliable-- there ought to be a simple user-accessible panel in the back, where you could remove & replace the lamps on these things, instead of taking the whole thing apart.  *bleah*

LED = Light Emitting Diode.  OLED = Organic Light Emitting Diode**.  These two are similar items, in that the individual pixels, like plasma, emit light directly, rather than allowing light to pass through.  This means a thinner panel, as you don't need to allow space for the lamps' to shine through the panel.  LED's are more efficient than florescent or luminescent lamps, too, but the lifespan of LED's is about the same as flouro.  Once an individual LED or OLED pixel dies, that's it-- it's done.  Enough dead pixels makes the panel annoying to watch.

Plasma utilizes the "neon" effect:  if you put high voltage through a gas, it turns into plasma, and emits light.  The color of emitted light is highly dependent on the gas mixture itself, with the now infamous neon being a familiar orange-red, and xenon being the familiar too-blue "white".  Mixing different gasses, you get different colors, and you can use filters, too. 

Combine all these, and you can get the requisite Cyan, Magenta and Green of the emmissive color wheel.  Black is the same as the others, the pixel is off, and the glass is tinted black.  For a plasma display, you have thousands of individual cells, behind color filters (I think-- it's been awhile since I looked into the tech of plasmas).  The heat should be obvious-- it comes from two sources, the individual plasma cells themselves are not 100% efficient, not by a long shot, and some of the waste energy comes off as heat.  The second source is the massive power-supply to convert mains volts into super-high volts for the cells'.  I think these are still too new to understand really long-term reliability, although nothing individually about it is new-- far from it. Neon is one of the oldest techs we know.  High volt power supplies are pretty mature, too. 

LED backed LCD's is just what you'd imagine:  instead of the flouro lamps to the sides, you have clusters of white LED lamps shining through the LCD pixels.  I would imagine these are always on, so long as the set is on, and that a single LED would illuminate a group of LCD pixels-- indeed, why not?  They are just being used as a light-source.  Longevity is too new to be established, but LED's are quite a bit more efficient than fluorescent lamps, so these ought to be the most efficient of the lot.

___________________

* an interesting bit, to the science geeks:  LCD's work by twisting polarized light through 90 degrees.   There is a polarizing back-filter behind the transparent LCD pixel oriented, say North-South.  There is a front-filter oriented 90 degrees from that, say East-West.  For light to get all the way through, it must be twisted.  This is where the liquid crystal does it's magic:  if there is no current, the polarized light is blocked by the front filter, and you have a black pixel.   If you apply a minscule voltage to the pixel element, the liquid crystal "untwists" and rotates the polarized light through 90 degrees, allowing it to come through the pixel and out the front.  The color of the pixel is determined by a final filter, just before the light exits the device itself:  Cyan, magenta or green.  Classic emmissive color wheel.

** Light emitting diodes are amazing solid state thingys, that if you pass electricity through, emit an extremely narrow-band color-- very narrow frequency spectrum.  The efficiencies approach 90% or more-- meaning little heat, mostly light.  To get broad-spectrum color, needed for rich screens, you simply mix different agents into one device, so that each microscopic "fragment" emits it's specialized frequency, but the over-all emits over the desired color frequency.  White is just a mix of several colors on the same device-- but you trade efficiency for color.  Organic just means that the material that does the work is not silicon or germanium, but some exotic mixture of organic molecules instead.  These are easier to manufacture than doped silicon/germanium-- you essentially paint the organic chemicals onto the substrate, rather than bombard them with electron-gun/plasma beam dopant chemicals.   One of the cooler things about OLED's is that, being painted on, instead of super-high voltage in a vacuum, you can paint them onto low temp plastics or flexible materials.  You don't need a very sturdy backing, like with traditional LED's.  Flexible displays could be printed onto fabric, for example.... 

Imagine walking around with a 'leather' coat that changed it's logo at the touch of a concealed panel inside...  the power for it, could be a piezoelectric device in your shoes, so that by walking about, you created power for your jacket's logo....

...a whole 'nother meaning to the sandwich-board adverts.  No?

[Sibling Zono (anon1mat0)]

Actually the beauty of LED backed LCDs is that you can create an algorithm to use them as a low resolution black & white display, the result is that the black areas of the screen have no back lighting making the blacks as black as they can possibly be having a very nice contrast. OLEDs are obviously superior but the biggest screen (15" I think) was sold by Sony in Japan for a humongous price. In five years the manufacturing of large screens should be economical to have affordable big OLED TVs in the market.

For now you can get OLEDs in cellphones (with the obvious advantage of less power and higher resolutions).

[Aggie]

Why I'm asking is that for the size of the TV the wife wants, plasma seems to be cheaper, and consumer reviews give me the impression that the picture quality may be better for plasmas (which as the old technology on the block, seem to mean that the sets remaining on the market are towards the top end) than for LCDs at comparable (slightly higher) prices. I don't see useage being high enough to make energy efficiency a factor, and in any case we are using a portable heater in the room where it will be living (so extra heat is appreciated!).

Part of the dilemma is that I'm trying for an LG or Samsung; however, I just found a deal on a Toshiba that at first glance might meet criteria and is priced acceptably at a local dealer:
http://reviews.cnet.com/flat-panel-tvs/toshiba-40rv525u/4505-6482_7-33248762.html

[Sibling Zono (anon1mat0)]

That Toshiba is LCD and a nice thing is that its 1080p (remember that most but the bigger plasmas are 720p) so its future proof.
---
I imagine you don't want me to depress you on the price of a similar TV I saw on Target this past black Friday (I didn't got it because I really didn't need it but was quite tempted).

[Aggie]

Y'all get much cheaper electronics - I know.   I am trying to decide if it's worth waiting until after Xmas for some Boxing Day deals (we do it backwards here).

Problem is though, I'm not so much concerned about future-proofing as 'past-proofing'!


Will need to physically get to a store and look at a few sets to see how they rank, and get some demos of SD performance.  _{Feeling a bit grumbly about this purchase, I think TVs are a waste of money so the less I can spend the better, but I'm also very big on value rather than just a low pricetag (i.e. best quality for the money spent).}

[Bob in a quantum-state-of-faith]

The internet to compare basics is fine.

But the personal experience of looking at the various sets, is a 100% must, in my opinion.

I eventually went to 9 or 10 different outlets, before settling on the WallyWorld purchase.

If you can, look for displays that are showing action-shots.  Those soothing displays of scenery do not show the real differences between the el-cheapo sets and the better capable ones.

For all flat screens have a graphics card inside (yes, exactly like a PC or Mac has). **All** image content these days has to be decrypted and processed in one or more ways, and your set has to be able to do this in 'real time'.

Some of the el-cheapo sets have a slow graphics processor, and you can see noticeable pixel-lag on really fast action scenes.

Some store displays will let you change channels into something with more actions, if you ask nicely.  I know I did.... and after explaining why, the sales reps were too happy to help, 'cause it would mean an up-sale.



(Except for walmart, wherein the "sales rep" wasn't old enough to shave, and hadn't a clue how the TV's even *got* their display picture, let alone how to change it.... but with some patient waiting, the scene eventually gave way to some sports clips, with lots of action... patience was the key, here...)