Progressive Scanning on 1080i?
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New member Username: JustintoxicatedPost Number: 1 Registered: Jan-05 | Ok I have been reading ALOT about TV's and first let me explain the question. 720p translated to 1080i on a CRT 1) First if normal TV is 480i, then you suddenly connect a digital TV connection or progressive scan DVD player to it how does your Normal TV become a progressive scan TV? Are all non HDTV's Progressive scan TVs? I thought that was just for EDTV? So then is a 1080i HDTV CRT Direct view Really interlaced? Or does it simply capabale of interpreting a 1080i signal? If it is simply a normal style TV with more pixels than why could it not show a 720p image? Picture this, since CRT's do not really rely on number of pixels for a given resolution, meaning there is no Native resolution (Main advantage of a CRT monitor is that you can easily change resolutions without distorting the image) So Picture a 22 inch CRT displaying a 1024x768 image @ 1024x768 resolution the picture will take up the entire screen. Now if you change the resolution to 1600x1200 the 1024 size image will be smaller but when you blow it up to fit the monitor with it's high resolution enabled you get the EXACT same picure as when you were running at 1024x768. Now a 1600x1200 image would look better but nothing was lost by blowing up a 1024x768 image to fit 1600x1200 ont he same monitor since the image displayed IS the SAME size and takes up the same exact pixels! My theory is that a 720p image would look identical on a 1080i TV and a 720p TV of the same size, However it would not max out the TV's capability. So when they say the signal is Boosted to 1080i on a CRT it should look identical to 720p on the same size display. (not true for LCD's) However I do not know if 1080i TV's screens are ACTUALY interlaced, or if it is just the signal that is interlaced to save space. If the CRT is truely interlaced, then 480P should look WORSE on a 1080i set than it does on a 480p (EDTV) Tv. So EDTV's look better when playing Progressive scan DVDs!?!??! From My experience (which is minimal) it does not. This leads me to my theory that although 720p images are blow up to 1080i Size that you will actualy recieve the SAME picture as a 720p of the same size at any given monent! Unlike an LCD that cannot directly Translate teh image size (although they can stillbe processed to look great) The Real question is wether or not CRT Tubes hardware is really interlaced. Seems poinltess to bother interlaching the TV when they can make the converter inside to display both 720p and 1080i and have a true dual TV since CRT does not have a native resolution. Now This Whole Concept falls apart with LCDs! LCD's are stuck at their native resolution. You cannot have an image look exactly the same on an LCD run at 1024x768 as it does on 1600x1200, when blown up the image may look distored especialy if the image size is not exactly 4 times larger (1 to 4 pixel translation or even 1 to 2) But CRT's can do this perfect because they do not rely on complex algorithms to balance things out. There guns adjust to the proper resolution and fire the image on the screen. So it makes sense that a 1080i LCD MUST fully convert 720p to 1080i signal and will not be displayed perfect (although it can be close), but a CRT could have the capability. The TV I just purchased is the Sony 30XS955. I have read several places that it can take EITHER signal, and depending how it is converted (If jsut blown up) you could enjoy all the advantages of a 720p. Maybe this is why they do not make 720p CRTs? From all the specs I have read the TV is both 1080i and 720p but I keep hearing that this does not exist (it is translated but is the 720p image really interlaced or just blow up?), However I have heard people playing games on x-box at 720p on a CRT blur less and look sharper than they do running the same game in 1080i mode! This would also confirm my theory that although there is upscaling it would not look any worse than if 720p WAS the native resolution. So then is a 1080i CRT really an interlaced tube? or is it just the reciever. According to many websites it does BOTH types of display in which a CRT SHOULD be fully capable of. What I do not Understand is how any interlaced TV would produce more "flicker than a progressive scan" an Image is still being displayed on 1/2 the pixels it is just not updated as often, so how exactly would this make flicker? It should simply allow for softer images and more motion blur and flicker should rely more on refresh rate. Another theory I had is that CRT's generaly have less streaking than LCD's do to begin with so therefor it makes much more sense to buy a 1080i CRT than an LCD since LCD's are already behind in that category progressive scaning should help motion on LCD's much more than it should on CRT's So I will leave this question to the experts! Oh yea, and since the X-box is not a progressive scan DVD player (and uses the X-box Connector which I dunno what that qualkity is comparable to) (unless in games) is it worth getting the Monster Cable's Components limited to X-box($50) Vs the MS HD kit ($20) and cables can be used for anything? Thanks. |
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xvxvxvx Unregistered guest | Your post is convoluted but from what I am able to glean you want to know if or why CRT's use an interlaced display and if or why an interlaced image would appear to flicker and why a 720p and 1080i would not appear identical. HD Crt displays display only 1080i because it is cheaper to convert all incoming signals to a single resolution period. Some older CRT Mitsubishis and Optimas would display both 720p and 1080i but they became too expensive to produce. 1080i appears to flicker because 50% of the information is missing 50% of the time, pretty simple. Your eyes can detect this due to the persistence of the CRT's phosphers. 720p and 1080i will not look identical. A 1080i display is discarding some of the 720p information and interpolating (scaling) other information. It is impossible for the pictures to be identical. xvxvxvx |
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New member Username: JustintoxicatedPost Number: 3 Registered: Jan-05 | A still picture would be compleatly Identical. This is PROVEN. Run what I said on any computer you have. Take a 1024x728 size image and set resolution to 1024. It takes up the whole screen. Then increase your resolution to 1600x1200 and also Blow the picuture up so it matches the resolution. The Picture Looks IDENTICAL. Ok thats because the image is using the same number of pixels to be displayed despite the higher resolution @ 1600x1200. THAT is the beauty of CRT's! That is the ENTIRE purpose of getting a CRT over an LCD. There is no Native resolution, just a maximum resolution. Images can be translated PERFECTLY to any aspect ratio of any scaling. Since the CRT is itself not interlaced then why would it degrade the image quality by interlacing a 720p image? SOunds like it would cost MORE and require extra work to interlace a non-interlaced signal. On an LCD this is NECESSARY due to Native Resolution restrictions, buton a CRT it is not. So your telling me the $1500 sony CRT (only 30 inches) that says it will do either 720p or 1080i will be locked at 1080i? When I went to the store it appeared to run both and tell me which mode it was running under. Also if the XS series does indeed convert noninterlaced images to interlaced, then why is it that some people report 720p having less motion blur than 1080i on this television? If the signal was converted to 1080i instead of just scaled to 1080 resolution then the image should simply look just as streaky and shoudl also have worse quality which would be VERY noticable, ratehr than looking cleaner and better? Also, I do not understand why it would be cheaper to have to add a converter to upscale AND convert the signal to interlaced rather than just letting it feed to the TV and stretching the image to fit. I would think that when they say upscale it, it should be simply enlarging the image to fill up the screen but should not take a 50% dump in frame display rate since that would be more complicated and more expensive if anything to convert than simply upscaling the image without changing the interlacing part. it is my understanding that converters are expensive... If I am honestly wrong about this sony, then what TV would you recomend (non DLP) to take it's place in my Bedroom for around 1500 that has better quality? it sounds to me just as bad to have a 720p LCD that constantly has to resize images from a non-native resolution to a smaller one and to Interlace the signal. Anothing thing is that you are telling me an EDTV would have cleaner playback from progressive scan DVD's than a 1080i HDTV would since the 1080i has to interlace a non interlaced signal? |
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Brent Stanton Unregistered guest | xvxvxvx, While I cannot really follow the above postings, I do have one question on ps dvd player. Say you have dlp or lcd, a progressive scan player sends out a ps signal for a smoother picture. My question is, what happens to the signal on a direct view 1080i crt? Does the tv reinterlace the signal making a ps player no different than a regular dvd player or does using a ps player still make a better picture? The reason I'm asking is I just bought a Sony direct view 1080i and want to know if I should buy a new ps player or keep my old regular player. Thanks |
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New member Username: JustintoxicatedPost Number: 5 Registered: Jan-05 | thats my general question also Brent, and it it does indeed to ps at 480p then why not at 720p also? otherwise I would assume a 480p (EDTV) would be superior to HDTV when watching movies, and possibly better than HDTV off the air since it is compressed to 1/50th of it's origional quality. |
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xvxvxvx Unregistered guest | A still picture would be compleatly Identical. This is PROVEN. Run what I said on any computer you have. Take a 1024x728 size image and set resolution to 1024. It takes up the whole screen. Then increase your resolution to 1600x1200 and also Blow the picuture up so it matches the resolution. The Picture Looks IDENTICAL. You are confusing the manner which a PC monitor processes and displays and how a TV processes and displays. So you have proven nothing about a TV display, all you have proven is that TV and PC monitor display circuitry is different. Now if you want to watch TV via your PC then you need to be posting in a different section of the forum. So your telling me the $1500 sony CRT (only 30 inches) that says it will do either 720p or 1080i will be locked at 1080i? Yes, of course with an HD input. When I went to the store it appeared to run both and tell me which mode it was running under. It is telling you what the input signal the unit is receiving, not the native resolution of your display. You can prove this to yourself since you admit an LCD will only display in it's native resolution. Go look at an LCd and change the input from 720p to 1080i and see for yourself. For that matter LCD's display at 768p so all incoming signals are scaled somewhat. I see later in your post you acknowledge of portion of this, just take your thinking a bit further and it will all make sense. xvxvxvx I will refer you to two webpages that will explain in detail what you wish to know: http://www.jonasjensen.com/HDTV720.htm http://www.alvyray.com/DigitalTV/Naming_Proposal.htm |
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New member Username: JustintoxicatedPost Number: 8 Registered: Jan-05 | Liek I said CRT's should be able to do this, if a Monitor can resize then so can a TV, they may be designed a bit differently but CRT's DO have this capability is my point, and my question was do they work they same, which your saying no to. Ok then, I still don't understand how a 1080i can display a progressive image, I know 1080i can only truely display 540p however it is more like 540px2 540p referse to the resolution it can change at once however the TV CANNOT be progressive if it has to convert to an interlaced format. What I mean is that an interlaced display CANNOT be progressive they are 2 different technologies, thats why 1080i is NOT really 540p. 540p would indicate that it has less resolution than 720p when it has more, it is just slower. Both arguments for both types of displays are stupid 1080i is only superior to 720p in some ways and visa versa, but 1080i is NOT 540p, it is however only the same speed as 540p in that the amount of pixels it can change at one time is the same as a 540p (in 1/60th of a second) but it has to do this 2x to update all pixels! Thus it is simply slower (pixels fire every (1/30th of a second). That is why I'm thinking an EDTV would look better in my other post because it would truely be progressive. Honestly 1080i should NOT be called 540p nor should it be called 540i, and 720p is NOT 1440i either!It should be called 1080i, it's the only thing that makes sense. Whoever decided to interlace anything should be shot. Thats why I'm saying that if a 1080i TV can truely support 480p then it can also truely support 720p, but when running at 1080i resolution it can only progressive scan 540 worth of resolution in 1/60th of a second, thing is that it is NOT 540 resolution it is 1080 so it takes longer. so even running 480p on 1080i would still have flickering and would not be progressive if the signal is interlaced although the TV has the capability to keep up with the DVD Player, it still has to update each half of the resolution at a time, as you say the TV can only work in one way interlaced. SO therefore it sounds like EDTV would put out a better picture for DVD than 1080i HDTV so it sounds like HDTV is falsly advertised. |
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Theil Unregistered guest | "What I mean is that an interlaced display CANNOT be progressive they are 2 different technologies, thats why 1080i is NOT really 540p" Not correct. A non fixed pixel display such as a crt can indeed be 1080i and 540p simply because it is not a fixed pixel display and does not have just one inherent native resolution like LCD, Plasma, etc., A crt can also display 720p however only more expensive models do so. Read xvxvxvx postings closer including the provided links. I am basically reiterating what was already posted. |
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New member Username: JustintoxicatedPost Number: 9 Registered: Jan-05 | Theil, That is what I said in the very begining (1st and second psots) was that a good CRT should be able to do either. they do not have a native resolution. Sounds like going CRT is by far the best choice I could have made. Anyone know if the KD-30XS955 Truely does both? Almost everything I have found on the net says it does, but the sony websites information does not confirm it and I have not gotten a straight answer from sony yet regarding the matter. I promise I will read the links when I get off work. However I thoguth 1080i was also what everyone considers 540p, so I was assuming that when he said it will run at 540p he ment the same as 1080i. However if it could run at TRUE 540p thenit should also be able to run at True 720p Due to the fact that this requires a change in resolution to begin with and 540p is not a standard. |
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Theil Unregistered guest | I assume you own the xs955. Excellent choice. When you ask if it does both do you mean progressive and interlaced? If so, answer is yes. Most will do 480p or 540p and 1080i. To run 720p would add considerable expense. All displays scale at some point depending on source material. 480i,480p,720p,and 1080i are the standards of source material but displays can scale to a number of formats. LCD's as mentioned above can scale to 768 (788 in Sony's case), crt's to 540p, plasmas can be 1024x1024 with rectangular pixels, the list goes on. The xs series is fully loaded with cablecard, ota hd tuner (free hd), and hdmi. Enjoy! |
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New member Username: JustintoxicatedPost Number: 10 Registered: Jan-05 | so the xs955 does not do true 720p? I was convinced that it did, I hope 720p signals don't look like crap then. |
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New member Username: Lobo65Post Number: 8 Registered: Nov-04 | I don't understand everything you are saying, but I can tell you that my Sony XBR960 has choices of viewing interlaced, progressive, etc. I don't know if the 955 does as well, but it's possible I suppose. |
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Bronze Member Username: JustintoxicatedPost Number: 12 Registered: Jan-05 | Yes it has choices and tell you what the signal is going in, but the question is what kinda conversion is going on. If I select 720p do I get 720p to 540p conversion or do I get sa 720p to 1080i conversion or do I get REAL 720p? I would assume that 480p is probably converted to 540p which would not affect image quality at all. But what about 720p? I beleive the BR uses the same tech as the XS but has some extra features. they do not make a 30 inch BR 960 which is the size I selected for my bedroom.(firewire and dual view) which I have little use for are included in the BR version. So if you find out if it actualy displays true 720p please let me know! |
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New member Username: Lobo65Post Number: 9 Registered: Nov-04 | Ok. Will do. |
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Bronze Member Username: JustintoxicatedPost Number: 13 Registered: Jan-05 | Damn I called the comapany I ordered from and asked where my TV was. I ordered it 3 weeks ago and they said they had it in stock and it would be here in 3 weeks... Well they said they never had it in stock and at this time it is undetermined when they will have it in stock again! I jsut wasted 3 weeks! THey should pay me interest on the money they "borrowed" from me when they lied to me! So I canceled my order. 3 weeks wated and it looks like I am going to have to pay full price now really sucks I'm tempted to just go without television at this point.  |
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Theil Unregistered guest | "I hope 720p signals don't look like crap then." The hs series which is a step below xs series does excellent job of 720p to 1080i ergo yours will excell. Tweeter, Rex, or other hands on store will give demonstration using an antenna. Go in during a football game when FOX or ABC is broadcasting 720p. I have a discriminating eye and could discern no quality issues from 720 to 1080. |
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Theil Unregistered guest | I must ammend my last post. The hs was demo'd with Samsungs latest tuner. |
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