How to buy ... a big screen TV

Of all the weird and wonderful gadgets in the consumer technology universe it’s still one of the oldest that we get asked about the most — the trusty TV. Of course, as technology has evolved, so has that classic question of “which TV should I buy?”. So if you’re having trouble telling your plasmas from your LCDs, then stop worrying, because we’re here to help.

The Big Picture
But whatever your budget, you’re going to want to spend it wisely. It’s a good thing then, that, at heart, buying a new TV is just the same as it was 20 years ago — you generally want the best picture quality you can afford at a screen size that suits. These days flat-panel TVs using LCD and plasma technology introduce a few new considerations to the mix, but it’s simply a matter of learning the pros and cons of each then concentrating on the fun part — picking a shiny new toy.

First things first, forget CRT. Yes, yes, we know there are still plenty of them around and even the big-name manufacturers have admitted this quaint old technology still has some life left in it yet. In fact, if you want a cheap TV for the kids’ room or the garage then by all means go pick one up. But if you’re shopping for a new TV that’s going to form the centrepiece of a home theatre system, you’ll need something a little more … newfangled. We recommend a large, flat-panel LCD or plasma.

LCD and plasma TVs haven’t been around that long and to begin with — aside from the fact they were seductively skinny — picture quality was average. Both technologies had problems reproducing deep black since by their very nature they always emitted some light, even when there wasn’t supposed to be any. This made for washed-out pictures that weren’t very nice to look at. Owners of decent CRT TVs with their deep blacks and great contrast were right to smugly deride these pretenders to the home theatre throne, but that smugness should have just about worn off by now. CRT TVs max out at about 36 inches and home theatre is only just warming up at this screen size. Modern-day LCDs and plasmas both sport sizes up to and over 60 inches and earlier image quality problems are all but gone … so which one should you choose?

LCD, plasma or something else?
This used to be an easy question to answer. Two years ago we’d recommend plasma every time on visual quality, size and price, but these days LCD has caught up in almost every respect, and surpassed it in some — screen resolution for one (see ‘Pixels’, below, for more on resolution). Rear-projection TVs (RPTVs) that use LCD or DLP technology have also improved markedly and now offer even better value for money than LCD and plasma, along with great picture quality to boot. However, an RPTV uses a projector, so it will eventually need a lamp replacement — generally after 8,000 hours or so though, which is quite a long time, really.
We’ve almost reached a point where we can say the technology is now less relevant than ever, as all three offer outstanding viewing experiences for a similar cost per inch of screen size.
A year ago we would have told you LCD couldn’t match plasma in terms of contrast and the price difference between the best large-screen (above 37 inches) LCD and a similarly sized plasma was too great to ignore. These days manufacturing costs have reduced to an extent that price parity isn’t far off.
Bottom line? Don’t worry about the type of technology a particular TV is based upon, instead look at price, features and picture quality. Become a technology agnostic.

How to spot a good picture
There are a few things you need to know about picture quality and how to tell if a display is any good or not.
Contrast is all important — it’s the difference between the lightest part of an image and the darkest. A TV with good contrast will produce a picture that gives the impression of depth. Black levels are just as important and are inextricably linked to contrast. When you go to a store take a DVD you know well with lots of dark scenes (The Lord of the Rings: Return of the King is our favourite). Get the store to play it and take a close look at how black the black bits actually are. If they look washed out check the brightness setting of the display and turn it down until it looks as black as possible without making detail disappear.
Colours should be rich but not oversaturated; check people’s skin tones — do they look abnormally tanned? Too orange? Turn the colour down until skin tones look normal and then check the rest of the picture to see if it’s still vibrant.
Don’t forget to try all the various picture-enhancing modes on offer to see what they do.
Ironically, an electronics store isn’t actually the best place to see a TV in action — with all the fluorescent lighting it can be hard to gauge picture quality — but if it still looks good after you’ve played with it for a while … it probably is.

You get what you pay for
The last thing to keep in mind when shopping for a new TV is that you get what you pay for. Despite prices tumbling, LCD and plasma TVs are still expensive purchases, so it may seem strange to start calling $2,000 displays ‘cheapies’. But it’s important to realise that even though we’ve been extolling the virtues of modern flat-panel TVs, it’s mostly in reference to late models. There are still plenty of older models out there with below-average picture quality and low resolutions, or even low-cost displays manufactured recently using previous-generation technology. You’ll probably still be pleased if you buy one, but don’t be fooled into thinking it’s anything more than it actually is.

Key features to keep in mind

Widescreen
Widescreen is the way of the future and there’s no avoiding it. Virtually all DVDs come in a widescreen format and if New Zealand ever gets broadcast high-definition TV that’ll be widescreen too. You’ve probably already noticed that it’s impossible to find a flat-panel TV (apart from the really tiny ones) in anything but a widescreen aspect ratio, and an increasing number of overseas TV shows are also shot in widescreen. Soon you’ll be the odd one out if you’re stuck with a boxy old 4:3 TV. How embarrassing.

Pixels
One thing all these display technologies have in common is a fixed pixel count. Whereas CRT TVs use an electron gun that ‘draws’ an image line by line, a fixed-pixel display has a screen that is made up of thousands, sometimes millions of cells or pixels, each one capable of lighting up independently of the rest. These are an unchanging and finite resource for your TV and together they represent the native resolution of a display. Whenever you see a plasma, LCD or RPTV, look for the resolution to be listed somewhere in the fine print — the higher the pixel count the better, because it means the TV will be able to display a finer, sharper image with more and better detail.
LCD holds the high ground in the pixel count war with good ones offering 1,366 x 768 and the best offering a staggering 1,920 x 1,080. Plasmas tend to be around 1,024 x 768 or 1,280 x 768 for some larger models.
But it’s no use getting caught up in a pixel count war since an internal video scaler is going to have to rescale virtually all incoming signals to match the panel anyway. If a DVD (containing 576 lines of horizontal resolution) is played on a panel with 768 horizontal lines, obviously it’s not going to fit. It’s the video scaler’s job to map the incoming picture to the display’s pixels. And it’s the quality of this scaling engine that determines the overall video quality of a display. We’ve seen a great many fixed-pixel TVs during the last couple of years, some with great pictures, some, well, some you wouldn’t take home to meet your mum.

High definition
HD signals come in a couple of common flavours: 720p, where the image is made up of 720 lines of horizontal information (a standard PAL DVD contains 576 lines) and 1080p. The USA, UK, Japan and even the Aussies all get to enjoy TV broadcast in HD. New Zealand’s motley bunch of broadcasters appear to be crossing their fingers and hoping no one mentions it so it might just go away. This will save them having to eat into their profit margins by investing in new HD cameras and equipment.

Blu-ray and HD-DVD
Both the Blu-ray and HD-DVD formats will only output their HD signals via the all-digital HDMI or DVI connections. This is no big deal if your TV has an HDMI or DVI socket, but a great many HDTV sets have already been sold and continue to be sold that don’t have such a socket — only the analogue component connectors. Ensure you don’t get left behind and look for a suitably equipped display.

Shopping tips




What your money buys you
With prices constantly falling, this table is a rough guide only.

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