Half-life, half truths, and TV myths

Interesting to read that Panasonic is now saying that the 'half-life' of its latest plasma TVs, such as the TH-46PZ81B (left), is in the region of 100,000 hours.

That's the amount of use it takes for the screen to drop to 50% of its original brightness – when it'll still be perfectly usable, just not as bright – and it equates to about 11.4 years of continuous use, with the set on 24 hours a day.

In the USA, where the statement was made, commentators worked out that means with an average of 6.5 hours' viewing a day, the set will be good for 42 years. And given my average viewing of around 4 hours a day – not so much in the week, but we tend to watch more at the weekends –, that would give us an expected half-life of getting on for 70 years.

So forget worrying about whether your TV will still be going strong come London 2012: on the current record of London as the host city, we should have had at least one more Olympics in the capital before the set needs to be put out to grass.

By which time I strongly suspect we all might have moved on to a new TV standard, let alone new sets. Not, of course, that I'm expecting to be around to celebrate the 70th birthday of any new TV I buy now.

But it got me thinking about the common myths flying around in consumer electronics, mostly coming from the mouths of babes, sucklings and the desperate on the sales floors of the nation.

Here's a very Top 10.

1. Plasma screens don't last as long as LCDs

Not so - see above.

2. Plasma screens need re-gassing after a few years' use
No, and I'm never quite sure where this one came from. Could it be because some old TVs needed degaussing if they were exposed to strong magnets – for example in badly-shielded speakers – ?

3. LCD screens don't last long
No. Reported to me by an amazed customer who'd been told "Well, your pocket calculators use LCDs, don't they? And how many of those have you thrown away?"

4. LCD screens are useless once the backlight goes
No, it should be perfectly possible to open up the set and replace the backlight, then it'll be as good as new. Whether it's economically viable, given the falling price of TVs, is another matter.

5. Plasma screens are no good for gaming, due to the risk of screen burn
Nope. Modern screens have strategies to avoid screen-burn – the permanent imprinting of static areas of light tones onto the screen. You see it in old panels used at airports or railways stations used to display timetables: when the signal goes down, you can still see the 'grid' on the screen. I have a plasma at least four years old, and it's never had a sniff of screen-burn.

6. There's no point buying a big flatscreen if you're only going to be watching standard TV
Again no. I'm typing this sitting in the office with a 32in Panasonic about 8-10ft away screening the Olympics - women's beach volleyball, since you ask – and it looks absolutely superb. And that's on a distributed aerial feed, with dozens of sets around the building hooked into it.

7. There's no point buying an HD ready set – Full HD is the way to go

Simple answer to this one - 8th-generation Pioneer Kuros, still among the best-looking TVs you can buy.

8. Flatscreens look worse than good old CRT TVs
Not really – see the answer to 5 above, and bear in mind it's unlikely you ever had a CRT much above 32-36in. Factor in the truly atrocious picture quality available on some Freeview channels, thanks to massive amounts of compression, and you have a recipe for disaster.

9. Product X is just as good as Product Y, and much cheaper – after all, the panels come from the same factory
No. That may be the case, but the two sets are likely to have very different picture processing, and maybe even totally different backlight technology. It's a bit like saying all CD players using the same transport or digital to analogue converter sound the same.

10. There's no point having a large TV – most films on DVD or Blu-ray have black bars top and bottom, so you're only using part of the screen
Plenty of point - you try watching a film in its original format on a 26in screen! The black bars are there as the film is being presented in the format the director intended. And if they really offend you, you can always use the zoom function on player or screen to give a full-screen image, provided you don't mind losing about 12.5% of the picture area from each side.

Andrew has written about audio and video products for the past 20+ years, and been a consumer journalist for more than 30 years, starting his career on camera magazines. Andrew has contributed to titles including What Hi-Fi?, GramophoneJazzwise and Hi-Fi CriticHi-Fi News & Record Review and Hi-Fi Choice. I’ve also written for a number of non-specialist and overseas magazines.