Dummies guide to Projection TV question..
Discussion
scared but happy said:
Right. Ok. I would like to buy a projection TV unit for the home.
Now what IN SIMPLE TERMS do I need to look for?
Lumans this and contrast ratio that. What is the difference in picture for a £500 and a £4000 one?
there are quite a few on Ebay but what do I need to have most?
Now what IN SIMPLE TERMS do I need to look for?
Lumans this and contrast ratio that. What is the difference in picture for a £500 and a £4000 one?
there are quite a few on Ebay but what do I need to have most?
Unless you are absolutely determined to go down the rear-projection route, I would strongly advise against it. The technology may be at its peak, but the fundamental losses that you get with a rear-projection TV simply do not compare to the picture quality that you get from a front projection setup.
The two credentials that you mention are equally important. Lumen's refers to the peak output of light from the projection unit - on the new technology LCD/DLP devices, they are measured differently from CRT technologies. That is why they always seem higher by comparison. The higher the lumen's figure, the brighter the picture, and on a front projection projector this is very important because the amount of ambient light in the room will effect the picture quality (that's why the light go down in the cinema). On a rear-projection TV its not that important as the whole light optics engine is contained 'in the box'. The most important value for rear-projection TV's (in fact all projection systems) is contrast ratio. This is the measured difference between black and white in gray scales (shades of gray). The new generation LCD/DLP series technology although doing slightly better of late, cannot compare to the contrast ratios that a CRT set can produce. As LCD/DLP projectors use a halogen lamp (the majority do) the lamp is 'on' all the time and therefore most of the projectors light control is dependant on the LCD/DLP panel and the 'colour wheel'. A CRT has the ability to turn off the light source completely and is not pixel dependant, so it can produce a contrast ratio in excess of 30,000:1 or more.. try finding that on a DLP/LCD system.
Rear-projection is dependant on a number of issues, one of which is the Fresnel Lens which has the job of passing the light from rear to front. On a conventional TV this would be made of glass, but here it is plastic. The two materials are incomparable as regards to light output, and not only will you only get a fraction of that light through, but you will also lose a very large viewing angle.
If you want to for a bigger screen, i.e. up to 36", then there are some good deals to be had with CRT in wide-screen now. If you want to go between 36" and 66" then LCD or plasma screens is the route. However if you want to go anything above and up to 25ft
then I would go for an LCD/DLP projector as they are cheap, although the lamps normally cost between £300-500, and they can go pop in less than 3months. If you want the best cinematic picture possible, you don't want to have to keep buying expensive bulbs and you want the ultimate in big/wide-screen, then a high CRT is what you want. The technology may be old, but its 'mature' and some serious equipment can be had for plasma money. I have worked on these systems for over 25 years starting off as a video systems bench engineer through all the technologies, and still maintain that Plasma/LCD/DLP technologies to be temporary until something new comes along or the product technology dramatically improves. If you choose to go down the rear-projection route, then you want to see the actual box you are buying setup and demonstrated in front of you, as I am yet to see a box which has been setup correctly to the standard that we used to set them to. Pay particular attention to the corners where the picture is hardest to converge, and notice that they may also be a lot dimmer there. If you see any red/green/blue glows around the objects, this is also due to setup and I would walk away from that model. Sony are a big player in this field.. ten years ago my house was full of Sony, now however it is my opinion that they are selling by brand-name and not by the same quality these products used to ooze. The one exception to this is the Sony G90 CRT front projector, which is one of the best projectors ever made; new these were over £30,000
but you can pick one up now for about £2000-3000, and its pictures will blow you away. If you get into this area, then there are only really two other contenders, and these are the Electrohome Marquee 9500 or the Barco Cine 9. edited to add quote to remind me what the hell I was replying to
Edited by ultimasimon on Thursday 10th August 21:07
scared but happy said:
Phew. Thanks for looong reply. I thought DLP and LCD are two different things?
So silly question would a £500 long as good as a £4000 one? For example a Bush TV picture looks the same to me as a Sony one.
So silly question would a £500 long as good as a £4000 one? For example a Bush TV picture looks the same to me as a Sony one.
Edited by scared but happy on Thursday 10th August 21:05
In all honesty you need to go and see them for yourself. I have added an extra bit of rambling when I was editing, so have a read. If you cannot distinguish between the two priced sets then go for the lower one! Also bear in mind that you need to be sitting a lot further back for a big screen and that you will also probably be able to see the lines in the fresnel lense from close up.. something that you would never had noticed with an old style tv. AS regards the difference, I would recommend the CRT based one over an LCD/DLP as you don't have to worry about getting the lamps changed. A CRT should go for between 10-20,000 hours before it needs servicing/replacing but the LCD/DLP lamp will need changing at minimum every two years unless you are very lucky. Let me see if I can find some stuff online to explain the differences...
scared but happy said:
CRT. Are they like the old pub style ones? I thought it was hard to align the 3 projections.
They do need to be setup correctly but there are a number of places that can do that for you, however if you are talking about a rear-projection box, then they are already set up as the size of the screen is fixed and set when it leaves the factory.
Plotloss said:
ultimasimon said:
What about LCOS and 3DLP?
Evening Matt
There are a number of new technologies emerging (thank God) but at the moment they are still in their infancy and reliability could well be an issue.. Remember the fabled Sony VW10
which revolutionalized Home Cinema... but then suffered huge problems with contaminated light engines and warranty returns..
Whats your take on the new stuff ?
If you are after front projection, then I had a Panasonic PTAE100 as my only tv for a year or so when they first came out and it was ok, but not really a tv replacement. Rear projection wise I had a 42" Toshiba RPTV, which just wasn't very good at all. Took a lot of work to get a picture undistorted and suffered a lot from discolouration. Moved on to plasma and never looked back.
However I have just bought a Toshiba MT200 projector from Dabs for £340 to get back into the home cinema lark, not received it yet (due to the Amtrack delivery driver getting lost!) but the reviews on the AVForums are very encouraging. For such a cheap price you can't really go wrong, especially since the ebay price for them is around £500 at the moment, so you could always flog it if you didn't like it.
However I have just bought a Toshiba MT200 projector from Dabs for £340 to get back into the home cinema lark, not received it yet (due to the Amtrack delivery driver getting lost!) but the reviews on the AVForums are very encouraging. For such a cheap price you can't really go wrong, especially since the ebay price for them is around £500 at the moment, so you could always flog it if you didn't like it.
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