I just visted some stores today and was able to see the RP DLP and RP LCD.
These would seem to solve both my lighting and angle viewing issues with RP CRT. The DLP's draw back was, no 1080i display only 780p. The RP LCD had both.
Can anyone tell me alittle more about these technologies.
I think I read on here somewhere that the picture qualities were not on par with RP CRT. They looked outstanding to me, but I'm new to this.
Thanks,
Tony
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well the thing with DLP is that it is necessary to have a dark ambient eventhough some say you dont need it. and by the way, DLP is not 1000:1 contrast as it claims to be. the next issue is the MEMS lifetime of the DMD. no one really knows how long until the pixels start to stick(known as stiction) to their substrate. I guess if you like good viewing angles LCD is the way to go but it is a very inefficient system(about 38%) since there is a lot of polarization going on. If i were you Tony, i would wait some 2-3 years before buy such an expensive light engine set.
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I looked at the Sony 50" LCD and the Samsung 50" DLP. Being a Huge fan of Sony I thought this was a no brainer for me. The more and more I research I went with the DLP. 720p vs 1080i was not a factor to me. I am a big sports fan and DVD watcher so 1080i was low on my list. I think the DLP is a better picture. It shows a true black color to me. I also liked the idea of 1 lightbulb burning out after 8000 hours is better than having pixels burning out over time.
My biggest hangup was Sony vs. Samsung. I get caught up with the bigger names sometimes. Then I remembered when I bought my speakers I went with a non-big name Paradigm which I can't be any happier with.
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From The Perfect Vision magazine, July/August 2003
Gary Merson
There has been a change in the marketing of high-definition RPTVs that merits your attention. The tradition of promoting and pricing HDTV according to the “good, better, best” business model has been skewed. When Sony first introduced transmissive LCD sets in late 2001, I sat back and figured, “Let the marketplace decide on whether this technology sinks or swims.” In 2002, Panasonic introduced its own LCD HD rear projectors. The proverbial “straw that broke the3 camel’s back” arrived, for me, with the latest issue of Consumer Reports. Dismay set in when I read in the March 2003 edition that CR had rated the 45” Panasonic PT45LC12 LCD as the best HDTV rear projector among the thirteen models tested. Consumers Union did not give the specifics about how it decided this set deserved a “top rating,” other than to say the score was based primarily on picture quality.
Transmissive LCDs are made up of three small panels (less than 2” each) sandwiched together to allow light to pass through them onto a screen, like a film slide in a projector. Let the truth be known: Transmissive LCD rear projection HDTVs make poor HD pictures! Price and sold as “the best” HDTV rear projectors, they are inferior to CRT, DLPs, and LCoS models. Here’s why.
Good high definition means more than a high pixel count (to qualify as HD, a digital fixed-matrix display, like transmissive LCD, DLP, or LCoS, has to have at least 720 vertical pixels). To make a good picture you need a good contrast ratio, as well as uniform color, good gamma (I will explain), good grayscale, a smooth structure (called fill factor), and long-term reliability.
Let me begin with contrast ratio --- the ratio of the brightest whites to the darkest blacks. Simply put, all LCD transmissive rear projectors have lousy contrast ratios. With LCD RPTVs, contrast ratio is so poor that Sony does not publish a figure for its Grand WEGA line, and neither does Panasonic for its LCD models. These projectors simply cannot make a dark black. And I have yet to observe one with a peak brightness that equals today’s CRT rear projectors.
Color uniformity is also poor with LCD RPTVs. When I generate a solid color field on the screen of an LCD rear projector, I observe areas of different hues.
Gamma is the ability of a display device to go linearly from black to white. The various LCD rear projectors I’ve observed tend to crush the light areas of the picture, causing brightly lit content to appear washed out and lacing in detail, like an over-exposed photograph.
As for grayscale, all the LCD projectors I have seen on showroom floors show a dark blue or purple in dark areas of the screen that should appear black. This may be color-correctable with as ISF calibration, though the dark areas will always be lit up no matter how low the brightness level is set. On the other hand, CRT HD rear projectors always hold black at black (when brightness is properly adjusted) and low-level areas are usually closer to neutral gray than they are with the LCD rear projectors I’ve observed.
Additionally, pixel structure is far more apparent in an LCD set than it is with other digital displays (DLP or LCoS) due to the greater amount of space between the panel’s pixels. (This has also been called the “screen-door effect.”) The larger the display and the closer you are to the screen the more apparent this anomaly becomes.
Last is the issue of reliability, i.e., dead pixels. In the transmissive LCD RPTVs I’ve seen on many showroom floors, most sets have had at least one dead pixel. Dead pixels can result in a permanent red, blue, or green dot on the screen. Moreover, I have seen LCD displays produce additional dead pixels as they age. Though such a thing is possible, I have yet to see an HD DLP display with a stuck mirror.
All the above factors result in a markedly inferior picture when LCD is compared to CRT, DLP, or LCoS rear projection. The only advantage to transmissive LCD over CRT rear projection is form factor: Light-driven displays can be made slimmer than CRT-based designs.
In conclusion, I cannot recommend any transmissive LCD rear-projection television. If you want the form factor they provide with a much higher quality picture, purchase an HD LDP (they are comparably priced) or LCoS projector.
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Thanks to everyone that's responded. You have saved me from more headaches. I will leave RP DLP and RP LCD on the backburner for now. My situation dictates I stay away from RP CRT due to viewing fom an angle. ( this will be a main TV and not a movie room TV). I guess I'll stick with
a HD tube TV for a few years and see were technology leads.
Tony
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>"I guess if you like good viewing angles LCD is the way to go but it is a very inefficient system(about 38%) since there is a lot of polarization going on."<
Could someone please explain why there's any difference
in viewing angles at all between the RP set technologies?
The viewing angles on all the various types of RP's
I've seen are all bad.
Thanks,
Carl
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Viewing angle for RP is based on the screen and technology used. Digital technology has a single lens in the middle which reduces angle errors while CRT has all three colors spread out over an area of about 1.5 feet. This is also what causes uniformity and color temp areas when viewing at an angle. Digital doesn't have that problem since it is a single lens.
Richard F. Fisher
Mastertech Repair Corporation, Lawrenceville, GA
770-513-3987 E-Mail - help@mastertechtv.com
Have you been calibrated? ISF and HAA Trained
Factory Authorized
Mitsubishi, Hitachi, Toshiba, Harman Kardon, Infinity, JBL, NAD
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I was referring more to image brightness and the hot
center spot that all RP's have.
The LCD RP's I've seen all seem to have just as much brightness falloff as any of the other types, yet
I see it repeated over and over that they don't
suffer from the problem.
I guess I'm not understanding how the chip or whatever point source the light is emanating from can NOT have
the problem when it's projected over such a wide area.
It would seem impossible to make a screen that could
distribute light striking it at such a narrow angle
evenly, especially if it needs to be thin and not in itself, visible.
Carl
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>>I was referring more to image brightness and the hot
center spot that all RP's have.
That is a function of the fresnel and lenticular lens - better known as the screen you are looking at. The purpose of the fresnel is to focus light towards the center to improve total light output at the correct seating position. This is what causes the beaming effect. The purpose of the lenticular is to reflect ambient light away from the screen as referenced to the viewer at the correct position. This is what causes the brightness to fall off dramatically at an angle.
It could be with LCD that there is so much light that they have reduced the effect of the fresnel and therefore the beaming artifact. I will speculate that a higher screen pitch may also improve angle viewing.
This message has been edited by mastertechtv on Aug 6, 2003 12:39 PM
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