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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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Posted to sci.electronics.repair,uk.d-i-y
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Arfa Daily wrote: snip There's no need for a display since it is theoretically possible to get all visible colours from RGB. Mixing dyes is a different matter. Theory, remembered from many years ago, suggests that isn't quite true. I seem to recall my colour TV lecturer at college, spending a whole session on 'the chromaticity diagram', and then explaining that there were certain 'non-spectral' colours such as brown, which could not be created by an additive mix of R,G and B, and any brown that was seen on the screen was actually some kind of orange or red, which was *perceived* as brown because of the surrounding colours, and other visual cues. That might not be exactly it, as this was all learnt nearly 40 years ago, but something close, I think. Think that was more to do with the deficiencies of the then tube colour cameras. Three or four tubes - usually Plumblicons. Which would show Magenta as bright green, etc. And of course many CRT sets didn't use the best phosphors - more concerned with how bright they'd go. As to whether LEDs as backlights do a good job, I'm sure that they must be at least as good as CCFLs at colour rendering, otherwise, the manufacturers wouldn't be making such a thing about it. Heh heh - advertising? I play with LEDs quite a bit, and they are getting better but still don't give as good a light quality as the best fluorescents. Flesh tones look perfectly fine on digital cameras which use LED backlit displays. Flesh tones contain a vast range of colour shades even on the one face - unless it's Des O'Connor's makeup. Wasn't talking about a quick glance. My whole issue with this, was that the LED 'angle' was being pushed by wording that *suggested* it was the main display technology rather than an LCD panel which it actually is, and which the great unwashed are now familiar with. That seemed to me to be a deliberate attempt to mislead people into believing that it was something new and revolutionary - as SED technology will be if it ever gets on the market, or OLED if they can get it big enough. Well yes and I agree. They're pushing them on TV too. But I haven't actually seen one. Perhaps they are as good as claimed. Cynical me doubts it. I don't have a problem with them claiming that this backlighting technique is revolutionary in TV sets - it is - and even claiming a reduction in power, if that's true, for a leg-up on the eco-bollox ladder, but I really think that they should be making that distinction, rather than trying to bamboozle prospective buyers with questionable use of terminology which punters are likely to have heard of, but won't actually understand. On the power consumption issue, I still do not feel that this technology is likely to consume anything like as much as the 100 or so watts that CCFL backlighting does. The developments in the light output of narrow-angle LEDs over the last couple of years is staggering. Some of the 1 and 3 watt types could literally blind you. I believe that some cars are now starting to use LED headlamps. It would be interesting to see how they stack up against the 50 watt consumption of 'standard' headlamp bulbs. More to the point to compare with HID in cars? Thing is for domestic light my preference is halogen, quality wise. Expensive fluorescent tubes can match that well enough. CFLs not. Nor any LED I've yet tried. -- *The severity of the itch is proportional to the reach * Dave Plowman London SW To e-mail, change noise into sound. |