View Question
Q: HDTV Resolution - Standards vs. Capability ( Answered ,   1 Comment )
 Question
 Subject: HDTV Resolution - Standards vs. Capability Category: Reference, Education and News > Consumer Information Asked by: rhworsham-ga List Price: \$10.00 Posted: 30 Jul 2002 16:28 PDT Expires: 29 Aug 2002 16:28 PDT Question ID: 47089
 ```What is the resolution (# vertical pixels x # horizontal pixels, or vertical and horizontal dot pitch)of typical Direct View CRTs which are HDTV ready? Specifically, I'm interested in the Sony HDTV models, with 32-36" diagonal Direct View CRT screens. Is this a sensible question? Also, why do reviewers say that the better plasma screens are fully HDTV ready when 1080i requires about 2 million pixels on screen while the highest resolution plasma TVs have a resolution of about 1 million pixels? (I realize that the number of pixels updated per second in 1080i is about the same as the number of pixels updated per second by the plasma screens because the former is interlaced while the latter are progressive, but this does not seem to be equivalent.)```
 ```Rhworsham, The only time that "insensible" enters this picture is the way I feel after sorting out all the HDTV specifications. I want my NTSC! Until there's a nice HDTV sale, that is. To calculate the overall screen resolution -- the total number of pixels -- of any TV set, you multiply the number of horizontal scan lines by the number of pixels in each scan line. For old times' sake, let's start with NTSC analog TV, the kind we've all grown up with. Although NTSC has a total of 525 horizontal scan lines, it only uses about 480 of these for the actual image. There are 720 pixels in each interlaced scan line, so our NTSC pixel calculation looks like this: 480 scan lines x 720 pixels/line = 345,600 pixels Rounding up slightly, we get about 350,000 total pixels on an old-fashioned NTSC TV set. The main promise of joy with digital HDTV (High Definition Television) is its much greater resolution. HDTV pixels are smaller and squarer than NTSC pixels, so HDTV can resolve finer details and hold smoother curves. Plus, you get considerably more pixels to look at. HDTV has a total of 1,125 scan lines, but it only uses 1,080 of these for the actual image (hence the "1080i" HDTV specification). There are 1,920 pixels in each interlaced scan line, so our HDTV pixel calculation looks like this: 1,080 scan lines x 1,920 pixels/line = 2,073,600 pixels Rounded off, an HDTV set gives us about 2 million total pixels, about six times the number of NTSC pixels. Obviously, there's a lot more visual potential with HDTV, something that also makes its movie-like 16 x 9 aspect ratio possible. NTSC only gives a 4 x 3 aspect ratio, which ends up whacking off the ends of a normal movie. You just can't see all those gladiators waiting in the wings like you can with HDTV. Sony's current HDTV models can be seen here: Sony Style HDTV & Widescreen (16:9) http://www.sonystyle.com/home/scat.jsp?hierc=9685x9421&scatid=9421 Only one Sony HDTV model with a 32-36" diagonal, direct view CRT (cathode ray tube) is shown: Sony Style 34" FD TrinitonŽ WEGAŽ High Definition TV KD-34XBR2 http://www.sonystyle.com/home/item.jsp?itemid=18111&hierc=9685x9421&catid= While an actual pixel count is not given, the KD-34XBR2's top interlaced resolution is 1080i, which means that it adheres to the highest HDTV standard (with total pixels as calculated above). One thing to remember about pixels: although a larger TV has a bigger screen than a smaller TV, the total number of pixels on the screen remains the same. There aren't more pixels on a bigger screen: the pixels themselves are just bigger, so the actual resolution doesn't change. If you get a big TV, you need to sit further away for it to look as sharp as a smaller TV. Now, let's look at the resolution of plasma TV screens, such as the Sony KZ-42TS1: Sony Style 42" Plasma WEGA™ Flat Panel Television KZ-42TS1 http://www.sonystyle.com/home/item.jsp?itemid=29213&hierc=9685x9421&catid= With plasma screens, you must consider their "native" or "addressable" resolution. This is the maximum number of built-in pixels which they can display. With the Sony KZ-42TS1, its maximum native resolution is 1,024 lines by 1,024 pixels. Let's do the math again: 1,024 lines x 1,024 pixels = 1,048,576 pixels Thus, we get about 1 million pixels, half the number of total pixels that HDTV is capable of delivering. Although the Sony KZ-42TS1 plasma screen is an HDTV monitor, and will accept all HDTV signals (it is "fully HDTV ready"), it simply cannot display all of the incoming HDTV pixels. Instead, the plasma screen "downconverts" the 2 million HDTV pixels so they can be shown on its 1 million pixel display. The more lines a plasma screen has, the higher quality HDTV picture it can display, but it still may not be able to match HDTV's full potential. While a plasma TV loses HDTV resolution (compared to a CRT), it may not be a full 50% difference due to the particular conversion methods used. Numbers and specifications can't completely determine overall picture quality, so you should try to compare different TVs side-by-side whenever possible. Comparing the relative resolutions of interlaced video images to progressively scanned images can be a little trickier. With interlacing, the TV displays one half of a video image (its even-numbered scan lines) first, then displays the other half of the image (its odd-numbered scan lines). Your eyes and brain put these alternately striped image halves together and you see them as a single, whole image. This is the same "persistence of vision" effect that theatrical films have depended upon for over a hundred years. Strictly speaking, only half of an interlaced image is displayed by the TV at any one moment. Using our current HDTV example of 2 million pixels, the TV only offers 1 million pixels at a time. Disregarding our persistence of vision, one could argue that only half of the available pixels are shown, and thus claim that the TV only delivers half of the potential resolution. The highest progressive scan resolution from an HDTV set is 780 lines. With 1,920 pixels per line, this gives us an approximate total of 1.5 million pixels. So, for a moment -- look *real* fast -- a progressive scan display could theoretically offer more resolution than an interlaced display. However, that's not the way I, or you, or anyone else sees it. Thank you, Huntsman References - In particular, the glossaries and FAQs on the following Web sites were very helpful. Corporation for Public Broadcasting Glossary: Digital TV Transition http://stations.cpb.org/pdfs/system/0106_digitalkit/glossary.pdf DigitalTV Zone All About Digital TV http://www.digitaltvzone.com/ DTV City http://www.dtvcity.com/ HDTV Info Guide http://www.hdtvinfoport.com/ Home Theater Magazine http://www.hometheatermag.com/ PC DTV http://www.pcdtv.org/ PBS Digital TV: A Cringely Crash Course http://www.pbs.org/opb/crashcourse/ Search Terms & Google Results - 1080i hdtv glossary ://www.google.com/search?sourceid=navclient&q=1080i+hdtv+glossary plasma screen hdtv resolution ://www.google.com/search?sourceid=navclient&q=plasma+screen+hdtv+resolution "persistence of vision" ://www.google.com/search?sourceid=navclient&q=%22persistence+of+vision%22``` Request for Answer Clarification by rhworsham-ga on 03 Aug 2002 08:43 PDT ```Thank you for a very good answer to my questions. Your explanations agree fully with my own research. If I could find a store showing plasma displays beside direct view CRT displays, that would be great, but I haven't been able to find such yet; hence the questions. This is even more fustrating, because my own calculations of the capability of the human eye to see HDTV indicate that at normal viewing distances and moderate sized screens, we can't see more than a million pixels anyhow. (For example, if you assume the resolution of the human eye is 1 arcminute, sitting 8 ft. from a 42" screen or 6 feet from a 32" screen allows you to see about a million pixels.) One clarification: Since Sony refuses to publish the resolution of their direct view CRT TV (they say no standards have been established for measuring resolution, and any specification might be misleading), how do you KNOW that the CRT can display 2 million pixels? What stops Sony from playing the same games with their CRT display that they play with their plasma displays - claiming HDTV capability just because the set can accept the HDTV signals?``` Clarification of Answer by huntsman-ga on 05 Aug 2002 14:04 PDT ```Rhworsham, I know what you mean: "specifications" can be pretty subjective at times. At some point, I guess you just have to trust the manufacturer. Although they may bend specs in their own favor, it is not in their best interests to give outright false or misleading information. This is particularly true for major manufacturers like Sony who command a large share of the market. I called Sony Customer Service today at 1-800-222-7669 and waded through their system until I got to operational tech support for Sony TVs. The tech I spoke to acknowledged that the actual pixel count for the 34" FD Triniton WEGA HDTV KD-34XBR2 is not available, he did say that this set accepts *and* displays the full 1080i HDTV signal: it is not downconverted. To get the facts from Sony users, I have also posted this question (under "huntsman") on the following third-party forum: AgoraQuest The Complete Unofficial Guide to Sony Products Forums > Television Misc http://www.agoraquest.com/forum.php The question is in their "Television Misc" forum, and has the subject line "Pixel resolution on KD-34XBR2?". I suggest you monitor this thread for any responses. Thank you, Huntsman Search Terms & Google Results: sony trinitron resolution pixels hdtv ://www.google.com/search?sourceid=navclient&q=sony+trinitron+resolution+pixels+hdtv```
 rhworsham-ga rated this answer: ```Excellent and very thorough research. By the way, the best overall discussion of digital TV I have found is at http://www.dtvmax.com/dtv.htm```
 ```using Sony's top line of HDTV's, the XBR series, I compared the resolution / number of pixels, and prices of Plasma vs. LCD vs. CRT/cathode ray tube/ 'tube' HDTV's : actual numbers on sonystyle.com for pixels/max resolutions of current XBR models as of 12/04: (i added retail prices) All Sony XBR (top line) models: Sony LCD 32 in. : 1289 x 768 = 983,040 pixels (\$5,499) Sony Plasma 42 in: 1024 x 768 = 786,432 pixels (\$7,999) Sony LCD 42 in.: 1366 x 768 = 1,049,088 pixels (\$9,999) Sony Plasma 50 in.: 1365 x 768 = 1,048,320 pixels (\$9,999) Sony Plasma 55 in.: 1365 x 768 = 1,048,320 pixels (\$12,999) ouch Sony Plasma 61 in.: 1365 x 768 = 1,048,320 pixels (\$19,999) ow bigtime Sony 34 in Tube HDTV: 1920 x 1080 = 2,073,000 pixels**** (\$2,199) link: http://www.sonystyle.com/is-bin/INTERSHOP.enfinity/eCS/Store/en/-/USD/SY_BrowseCatalog-Start?CategoryName=xbr&Dept=tv -------------------------------------------------------------------------------- also - the resolution / number of pixels for the CRT tube hdtv 34 in. was not given on sonystyle.com, and customer service said that it is "unpublished information". thats pretty shady huh? i think its obvious that if they reveal that the cheapest hdtv also has twice as good a picture- that would hurt the sales of their plasma and LCD tv's. trickery! -Mike```