Help with TV questions (1 Viewer)

[ChrisLazarko]

I was wondering the difference between DLP's, Plasma's, RPTV's and LCDS. Could anyone give me a site on where it shows the difference between them all and perhaps life-spans on the bulb and what you can do once it dies?

 

[scott>sau]

DLP=digital light processing front projector (PJ). Texas Instruments developed the chip for it. It is the hottest thing sense ACT II popcorn because it has better brightness uniformity on the screen, more clarity and more lumens (brightness) than other types of projection. DLPs are HDTV. Plasmas are the flat screen TVs (Hi-Def). RPTV are those boxy, refrigerator sized TVs. They have the CRT (3-lens, red, green and blue tubes inside that fire into a mirror, then in the screen). They have the worst picture from any you are inquiring about. They are also heavy. LCD's are more for business presentations. They are not as bright as a DLP. They produce a "screen-door effect" in which if you move close to the screen it looks like a screen door (cross hatched). Not as clear as DLP and not hi-definition. The bulbs in a LCD typically last 2000 hours. They are $400 to replace. You can replace them yourself. www.projectorpeople.com offer free, unbiased information on types of projection. P.S. I am glad you didn't inquire on the CRT PJ. It is dying per Sam Runco. Parts are rare and will not longer be made. They require a ISF grayscale calibration each year ($600). They do offer pretty black levels and a smooth picture, but are like maintaining a fancy sports car. DLPs is your best bet. InFocus has a SVGA (the X1) for $1000 XGA's are better. Hope this helps.
Scott

 

[ChrisWiggles]

Pardon? I think there are many who would strongly disagree with that statement. Well, you are correct about the big&heavy part.

You don't need to pay to have it calibrated all the time, having it ISFed may give you a good improvement depending on the skill of the tech with your particular set, but you can do convergence yourself easily enough. RPTVs while generally still CRT-based (thus no bulbs to burn out, but you do have burn-in and such that may be of concern), but many RPTVs now use DLP projectors and the like inside instead of CRT projectors.


"DLPs are HDTV"

No.
Any of these can come in a variety of different resolution capabilities, HDTV or otherwise.

Plasmas have a "coolness" factor, but you can do much better for the money. A RPTV (CRT-based) would probably provide you with the best picture, but between that and a front-projection DLP, i'd go with the DLP myself for probably around the same cost. CRT FPs(used of course) are probably still the undisputed king unless you're willing to shell out some VERY big $$$$, $$$$$$ $$$$$$$$$..(omitted $ signs ) ..$$$$$$$$$. FP CRTs are probably more of a hassle than what you're prepared for, and more than pain than an RPTV, but it's always an option(the best option still?... perhaps).

Bulb life and price varies widely by projector models(bulb models), not by type of projector, per se. CRT tubes last a long long time, unless you don't know what you're doing and burn them by not calibrating your display properly, or trying to push it to high contrast levels, or game a lot with static images.

 

[scott>sau]

From Wiggle: "CRT tubes last a long long time" False doctrine fur sure. Ever hear of "scan fail"?

Sam Runcos thoughts as addressed to the AVS Forum on why the CRT front projector is dying: "The lenses were the first problem we encountered, but it's onlt the beginning. The next challanges will be obsoleted parts that have no comparible replacement and projection tubes. I don't think there will be replacement lens makers. Too expensive. We at Runco have no aim to make more. Runco is in good shape for 3-5 years as we fore-casted til then. The supply for most CRT parts will sonn be gone". (He was a AVSF special guest in 2001.
Chris L. don't get a RPTV, their image is inferior. Hope this helps.

 

[ChrisWiggles]

Maybe you could actually read through what Sam wrote:

"A properly installed and set-up CRT in the proper ambient environment is still the best picture. "

Perhaps you should also take a spin to the other special guests, including the guy from Barco (who makes runco's CRTs now), or stop by the CRT forum that is alive and well at AVS. Sure, CRT is probably not for 99.9% of people out there, but if you know what models are good and not prone to failure, you can easily get your hands on a pristine projector for a couple grand that will obliterate any competitively-priced new displays out there.



That is not true at all. There are many reasons NOT to go RPTV, but the idea that poor PQ is a reason is laughable.


I will quote from Barco:

"
While today’s DLP or LCD projectors offer good results for computer data and graphic images, experts will confirm that CRT projection technology still provides the best possible picture quality and most realistic images for video display applications. When it comes to a Home Cinema projector, and parameters such as black level, dynamic range, picture resolution and compatibility with a wide range of standards without scaling (and the unavoidable artifacts of the scaling process), the technology of choice is and remains CRT.
"

There are whole hosts of reasons why the pros such as Guy Kuo from Avia still use CRTs. And there is a reason why I am willing to undergo the pain in the ass it is (yes TOTAL pain in the ass) to get a 150+ pound monster up on my ceiling, then go through the computer nightmare of building an HTPC to be able to feed it beyond hi-def resolutions. You're right, a CRT-based RPTV may not be the best option (surely a FP CRT probably isn't) for Chris, to say that they offer far inferior PQ is ludicrous.

As to why CRTs are dying...it's quite simple really: small, portable, bright, easy to set up, mobile,(digital projectors) versus EXTREMELY large, heavy, totally non-mobile, very challenging to set up(with continuing re-convergence), not good with ambient light(CRTs). Lastly, cost...new CRTs are still very expensive, whereas digitals can be had very cheap. Add to that lack of deep consumer knowledge, so that PQ takes a rank of importance somewhere further back.

 

[scott>sau]

CRT front PJs have good levels of black, but when my Barco Data scan failed I got a DLP. It has a great, bright, colorful picture. Chris, very true about the CRT weight, my Barco weighed in at 180 lbs.:frowning:
What ever happened to ChrisLazarko?

 

[ChrisLazarko]

Well i'm here. I'm simply asking these questions to further my knowledge. right now I own a rear-projection 50" Mitsubishi TV and have no need to change or want to change.

I see alot of people have biased opinions but other than biased I just want the facts. I don't understand what a DLP is to this point still? I know RPTV's are Rear-projections and the bulbs usually have a life of 50,000 hours. As for LCD's I have heard that they usually have the same lifespan but they have that small problem of being pricey and having dead pixels.

And what is this with everyone saying Front Projectors? I though that unless you want a projector in the back of your head that everything was rear-projected?

Thanks for the help guy. I need to know alot about TV's and stuff... kinda trying to find a job as well.

 

[ChrisWiggles]

You should probably peruse the Display devices forums.

Just to clarify, RPTVs are Rear Projection TVs. That is, they are self-enclosed units that have a video projector that bounces off a mirror in the back and onto the rear of the screen. The actual projector can be any type of projector, but until recently they have been CRT-Projectors.

CRT projectors do NOT have bulbs, they use Cathode Ray Tubes, three of them, one for each primary color (red, green, blue). The images are drawn on the surface of each tube, and then each color image is converged(aligned) perfectly onto the screen to create a full-color image. This is the same technology (CRTs) that are used in regular televisions, except that in a regular, smaller TV, you are looking directly at the face of a single CRT tube that creates all three colors on it's face.

The other types of projectors now used are digital projectors, which use light bulbs unstead of the old-style CRT tubes, with a DLP chip, LCD panels, LCos, (maybe there are others i'm forgetting).

DO searches and read up. Plasmas and LCD panels function differently. Keep in mind that a Rear-projection TV is just a projector built into a big box with the screen included. The systems should be similar to a regular front-projection unit.

And yes, front projectors can be mounted in 4 standard ways (other ways require more creativity, and mirrors and such), either on the floor/table, on the ceiling, and each of these in both front and rear-projection setups. In a rear-projection setup, the projector is put behind the screen, and thus requires very significant room way behind the screen to put it behind the screen. An RPTV does this on a much smaller scale, the projector is in the bottom of the set aimed up and to the rear at a mirror, which bounces the image to the screen. And a front projection system would be very much like a theater, with the projector above or behind the seating area(unless you're doing a table mount, then it's somewhere in the seating area). This allows you to get any sized screen(within reason) you want, and much bigger than most RPTVs.


Ok i hope i covered some of the information, the pros and cons of each of these technologies are more in-depth, you should read, then ask other, specific remaining questions on the display forums here and over at AVS(very good over there).

Oh, and as for what DLP is, it's TI's Digital Light Processing, it's a DMD chip with a mirror for each pixel that can turn on/off to create whites and grays and blacks. (some would say they are not yet capable of producing true black, but they can be damn good if you're not being extremely videophile-picky). The image then goes through a color-wheel to add color(3-chip DLPs have a chip for each color instead, but this is at the extreme high-end still), there's a little demo on Texas Instrument's site somewhere that explains it well. The image is then projected onto the screen.

I have to say I've more been following front-projectors, which translates a little bit into RPTVs(which as explained are the same thing really), so I can't really explain Plasmas or LCD panels to you that well, but they aren't really up to the image quality of a good RPTV, IMO.

There are a lot of trade-offs and reasons to get one technology or another, but don't forget that image quality is indeed important.