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Discussion Starter · #1 ·
Someone help. i want to buy the KP51WS510 sony 51 inch projection hdtv but the most important aspect of the specs i cant find anywhere. This is more a question about all RP CRTs in general. Do they have a native resolution of 1920x1080 or 1280x720 (like most plasmas). This confuses the hell out of me. only plasmas and DLP tvs show the actual resolutions in the specs. All it says is its capable of accepting 1080i,720p and 480p. but that doesnt mean anything to me because i want the actual display of 1080i or 720p. Is this sony RP Crt just a crappy 480p that can downconvert 1080i??? Does this tv or any crt RPs display 1080i or 720p???
 

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I believe that unit is native at 1080i. It will accept the other resolutions but will internally scale them to its native 1080i.


The 1080i units are 1920X1080, the 720p units are 1280x720. Plasmas and Lcds have a slightly different resolution, usually around 1366x768, but are pretty much in the same bucket as the 1280x720 units.
 

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Discussion Starter · #3 ·
but 1080i is just 540 lines of picture with 540 interlace black lines inbetween right? so its basically just 540 lines spread out to give you the effect of 1920x1080? so does that mean that 720p dlp tvs are better off because they can show 720 pixls in a row without black scanlines inbetween???
 

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While it is true, that 1080i actually shows only 540 lines at any one time, you have to realize that you can't normally perceive that. The CRT draws the odd lines/fields in a 60th of a second, and then the even lines/fields in a 60th of a second, combining the fields into frames of 1080 lines, every 30th of a second.


As far as native resolution, most CRT's claim a native 1080i, while FPD's usually are 720P. The ultimate short term goal is 1080P, which we are already seeing displays like LCOS do. Samsung is trying to bring out their 70" Plasma that has a native 1080X1920, by next year. Ti is working on the 1080X1920 native DLP chip, and there are several other technologies capable of this on the horizon as well. The problem with CRT is that they are usually not considered to fully display 1080X1920 unless they are using 9" guns. I have heard many engineers say that the best resolution for many of the 7" guns is about 640P. We are dealing with two equations here, the available raster (a 9" gun has more area to draw on), and the upper limits of that particular chasis scan rate. Some set's can only scan up to 15.K, others can go to 100K. So, although 720P is lower overall resolution, it has a higher scanning frequency, so that is why many CRT's can do 1080i but not 720P.


480i = 15.75 KHz (Horizontal freq.)

480P = 31.47

720P = 44.95

1080i = 33.72

1080P = 67.43
 

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Quote:
This is more a question about all RP CRTs in general. Do they have a native resolution of 1920x1080 or 1280x720 (like most plasmas).
CRT-based RPTVs use relatively compact electrostatically focused tubes, usually 7-inch diameter. These aren't capable of resolving 1080i's full potential horizontal detail. And CRT RPTVs with native 720p capabilities are no longer being marketed. Instead, 720p is sideconverted to 1080i.


Very costly graphics-grade front projectors with 9-inch CRTs, using electromagnetically focus CRTs, can focus electron beams narrowly enough to resolve HDTV fully. This earlier article outlines the stringent technical requirements necessary for this.


A review last year of a Mitsubishi RPTV with 9-in CRTs (electrostatic) indicated it could resolve 1600 horizontal pixels. This firm has slated more RPTVs with these larger projection tubes. But how much resolution is required? The article linked explains why the limiting horizontal resolution of 1080i (sampled) is about 1700 pixels horizontally (cameras and telecines). That's separate from the format, 1920X1080. Earlier I outlined differences between resolvable horizontal detail and the standard 1920X1080 format. Here's another post that goes into this topic. As these posts/sublinks outline, there's less HD detail--horizontally and vertically--being delivered and displayed on home screens than you might expect. -- John
 

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Most sets these days resolve 1280 lines max. So you could consider resolvable resolution as 1280x720p for LCD and DLP, and 1280x1080i or 1280x540p for CRT.
 

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To say that current sets do not resolve 1920x1080 would be inaccurate. They do, as I have done it with my own set. Granted text is hard to read, but that is because of the poor dot pitch. Even though text is somewhat hard to read, computer games and expecially jpegs from a 4.0 megapixel camera look breathtaking at that resolution. If you need to read text, you can bump it down to 1440x1080 or 1280x1080.


What it boils down to is that current sets are barely anymore advanced than old analog ones. They are nowhere near as advanced as a computer monitor, and are still pretty much limited to a fixed resolution. Therefore you won't find a consumer grade set that will display 1080i and 720p natively.


NEC is the company to look at if you want something that behaves more like a computer monitor. They have very large direct view monitors and even some rear projection monitors. They've been making them for years for industrial use. The price reflects that.


-spazzman
 

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RPTV's most all do 1080i,but the 2nd number which is the pixels at 1980 would be true full capacity number of pixels capable within a 1080i broadcast. That this time no set does 1920,but instead does more like 1280 or so, some only 1000, but at this time most broadcasts are only around 1440 pixels either, so even if your set would do it, the broadcast isnt.


I don't do Sony but if you are looking at CRT based Sony, thebig gripe on them without even considering pixels is the heavy flickering of the image, and make sure that doesn't bother you before you buy, because it definitely exists, and drives many peoplenutts.


There are many arguments whether even a 9 inch CRT is capable of doing 1920 pixels, no matter who makes it, but at the same time only Mitsubishi is getting ready to put one in their upcoming 04 Diamond line, in the 65813, which is slotted for end of October release. At the same time one of the earliest high end CRT based sets was the Marantz at $11,500 in 1999 and it was 64 inches and had 9 inch CRT's but in their specs they clearly said it did do full 1080ix1920 pixels, so if it didn't in fact do that, every owner could have returned it on that basis whenever they wanted under product deception, yet I never heard of this happening, so I am inclined to think that a 9 inc CRT in some cases can actually do it.


Best of luck and I hope whatever you get, you like it.
 

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Quote:
Originally posted by spazzman90
To say that current sets do not resolve 1920x1080 would be inaccurate. They do, as I have done it with my own set. Granted text is hard to read, but that is because of the poor dot pitch. Even though text is somewhat hard to read, computer games and expecially jpegs from a 4.0 megapixel camera look breathtaking at that resolution. If you need to read text, you can bump it down to 1440x1080 or 1280x1080.
No sir...your statement is innacurate. Yes, it can accept 1920, but it can not resolve all the detail. I think you are getting a bit confused at exactly what we are referring to.
 

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No sir...your statement is innacurate. Yes, it can accept 1920, but it can not resolve all the detail. I think you are getting a bit confused at exactly what we are referring to. [/quote]


Ok, I guess the confusion is coming from the word 'resolve'. The TVs do more than accept the 1920. They display it, or they display something anyways. I guess I am drawing a parallel from back in the old days when computer monitors started to surpass standard VGA resolutions. You could buy a monitor that would do say 1024x768. The only problem was that the dot pitch was so poor, the picture looked out of focus and you would get a headache in half an hour. All HDTVs include digital circuitry. Therefore there must be a pixel grid. I believe that the ATSC has stated the pixel grid must be 1920x1080. Not 1440x1080 or 1280x1080. Therefore your TV must display 1920x1080.


I would like to hear more about this from you. I'm sure you could maybe explain to me if I am not looking at 1920x1080, what am I looking at? I understand resolving detail in the old world of analog tv, however does it apply in the new world of digital TV and fixed resolutions?


Thanks again,


-spazzman
 

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Hey Marc,

those phillips sets w/9" look great. What do you know about the etailer. Reputable? Were there any known issues with the phillips/marantz?


Thanks,

Paul
 

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Interesting to see Marc's link above indicating the 9-inch-CRT Philips/Marantz RPTVs, or their cousins, are still available. I bought the Philips (64PH9905) in mid-2000 and it's still spitting out great images. There are earlier posts that distinguish features and differences.


Yup, Philips claimed it'll provide full 1080i images, or some similar wording. But my views on what that means have evolved over several years. Suspect, from the review of the 9-inch Mitsubishi I mentioned above, plus earlier threads on the Philips/Marantz RPTVs, that they can resolve 1600-1700 pixels/lines horizontally. As mentioned above, and as the sublinks cited outline, ~1700 pixels horizontally is the limiting resolution of all the sampled HDTV we ordinarily see--camera or telecined-film originated. Test patterns from electronic generators or computer graphics aren't sampled and can put 1920 alternating B&W pixels across displays capable of resolving them.


If a CRT display can't resolve 1920, 1600, 1300, etc. alternating B&W pixels from a test pattern you'll see a continuous tone. That's because, if 1920 resolvable B&W pixels were present originally, the higher HD frequencies generating the most detail have been filtered (reduced). The pixels haven't vanished, there's just not enough contrast between the more closely spaced pixels so you can resolve them. (Also, CRT beams, within RPs or FPs, may be too thick.) So you can have a 1920-pixel-wide horizontal line (standard HD format), but the 1080i production process may only be delivering resolvable horizontal detail, maximum, of 1300 pixels. Here's a recent thread claiming tests of a ~$75k professional HD recorder shows it compresses telecined films (not test patterns) to less than 1300-pixels resolvable detail. Again, that's still with a 1920X1080 format. -- John
 

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It is true, that a monitor can be called HDTV capable, and not really be capable of the full resolution. Few sets on the market are capable of true, full spec HDTV (1080X1920). Fully aware of this, the ATSC has spec'd many different scan rates for DTV. Because of the difficulty in doing 1080i for most FPD's, they have approved 720P as HDTV as well, since that is what most FPD's are currently relegated to.
 

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Quote:
Originally posted by Paul Clancy
Hey Marc,

those phillips sets w/9" look great. What do you know about the etailer. Reputable? Were there any known issues with the phillips/marantz?


Thanks,

Paul
This etailer is Philips' authorized outlet/clearance house. They have received good reports over in the direct view forum and on ebay (they use to operate solely on ebay). I almost bought a 34" from them before deciding to get a Hitachi 43" (800-1000 vs. 1280 resolvable horizontal lines of resoluton).
 
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