High Definition Television, U.S.A.
Updated May. 2001
Ideas and hints and inside information to help you better understand the upcoming U.S. HDTV system, when it should be on the air, viewing it on your present TV set. Things to be aware of when shopping for an HDTV set.
Get into any discussion about HDTV and you will surely hear that HDTV gives you a picture 1920 pixels wide by 1080 scan lines high contrasted with regular TV's 525 scan lines. The good news is that most HDTV ready sets today can display almost* 1080 scan lines with almost* 1920 pixels on a line. The bad news is that they can't display that much picture detail all at the same time. The shortcoming is that the TV cannot make dots that tiny or lines that fine so picture details occupying consecutive scan lines or pixel positions are blurred together. (* A few scan lines and pixels are lost at the extreme edges due to overscan.)
All parts (c) Copyright 1997-2002, Allan W. Jayne, Jr. unless otherwise noted or other origin stated.
Diagonals versus Details (2/99)
Convergence and Dot Pitch
See HDTV On Your Old TV (1/99)
HDTV or DTV? (1/99)
Projections
Choices
With your existing TV set
With a new HDTV set
With your VCR
Cable and Satellite
Video disks and prerecorded tapes
What broadcasters can do
Be Careful Buying HDTV Set
Who Will Buy What?
HDTV Scan Rates and Similarities
The two most common formats of U.S. digital TV are 480p and 1080i. They are handled and they behave similarly as far as the TV electronics go.
The 480p video consists of 525 scan lines (480 hold the picture) repainted on the picture tube every (approx.) 1/60 second. The total number of scan lines per second is about 31,500, or we say the scan rate is 31.5 KHz.
The 1080i video consists of 1125 scan lines (1080 hold the picture) repainted every (approx.) 1/30 second, as two 562-1/2 line fields for 540 odd and 540 even lines of picture information, respectively. The scan rate is 33.75 KHz.
Since the scan rates for these two formats is almost the same, it is usually not necessary to have separate calibrations for convergence, overscan, geometry, etc. for each format.
Horizontal resolution capability is actually about the same for both 480p and 1080i for most HDTV sets. The same limitations, electron beam spot size, dot pitch, video amplifier bandwidth, etc. affect the horizontal resolution for HDTV and DTV as well as for the older analog video. We usually don't run into the horizontal resolution limit with 480p since most HDTV sets can resolve more than 720 pixels across the screen which is the upper limit for current 480p program material.
"Regular" NTSC video has 525 scan lines, about 480 holding the picture, repainted every approx. 1/30'th of a second. Some HDTV sets, instead of "gearing down" the picture tube scanning to 15.75 KHz to display this, convert the NTSC video to 480p using a circuit generally called a line doubler.
Even though your computer monitor (monitors with CRT's) is referred to as displaying 640 x 480 pixels in regular VGA mode, the actual number of pixels across can be whatever the input source wants it to be. The CRT can just as easily display pixels spaced 1/720'th the screen width when it is in 640 x 480 mode.
The difference between 1080i and 540p is that, in the former, the 540 scan line odd scan line field is staggered slightly upwards and the even field is staggered slightly downwards. If the staggering were not done, half of the picture vertical detail would be lost. A few sets also apply the stagger to their 480p video which could then be called 960i, but the even and odd fields thus created are identical in content, the program material does not possess more detail to reveal.
The other HDTV format, 720p, is used occasionally but not commonly in over the air broadcasting. Its scan rate is about 45.5 KHz which is far enough from the scan rates for 480p and 1080i so as to benefit from a separate set of convergence and calibration settings and "memory" in the TV set. It also requires much better quality video circuits to display spots 1/960 the screen width which is half of the 1080i resolution, let alone 1/1280 the screen width which is the 720p resolution.
Display vs. Resolve -- All at the same time
Except for the cheapest or defective sets, and a few that fit into a certain manufacturing loophole, today's HDTV sets can display 1920 pixels across by 1080 scan lines high minus picture edges lost to overscan. By this we mean that a tiny dot or thin line can be seen to occupy any one of 1920 pixel positions horizontally and/or 1080 pixel positions vertically. But almost no HDTV set today can resolve picture details occupying all pixel positions simultaneously. One reason is simple, the smallest dot that can be produced is more than 1/1080 the screen height and more than 1/1920'th the screen width in size. A resolution test pattern has dots or thin lines very closely spaced. The resolution of a TV set can be easily determined using such a pattern, although no such patterns for HDTV are readily available to the consumer.
The Loophole
While US DTV (1080i, 720p, and some 480p programs) are meant to be shown on a 16:9 screen, most HDTV sets have 4:3 screens. Manufacturers are still permitted to advertise their sets as HDTV when the 1080 or 720 scan lines occupy the entire 4:3 screen and in order to display the entire 16:9 picture, only the inner 810 or 540 scan lines, respectively, are utilized. Immediately the number of possible vertical positions for a tiny dot is reduced to 810 or 540. In addition, the circuitry needed to convert what were once 1080 scan lines to 810 may reduce the horizontal resolution.
U.S. HDTV -- Our Projections (Jan. '98)
Our Recommendations, or, In A Nutshell:
If you are an average viewer, just continue to use your existing TV sets. Try to hold off at least four years.
After a lot of HDTV programs become available, buy a converter box to see them with today's quality on your existing TV sets (we estimate 2 to 3 years from now). Most likely, even after you buy an HDTV set, you will continue to use the converter box with an older set elsewhere in the house.
If and when you the average viewer are ready for HDTV, take your time before buying a set that has the features you want and fits your budget. Prices will be a lot lower three years after the first HDTV sets are offered for sale.
If you are an electronics whiz who always buys the latest gadgets, don't let me stop you.
The current technology in filming movies is such that HDTV may not always look noticeably better than the same program on today's TV.
May 2001. It is just over three years since the above projections were made. HDTV ready sets that can display 1080i and 480p can be purchased for about USD $2000. with resolution about 1/800 to 1/1000 the screen width. Less expensive sets that can resolve details 1/600 the screen width are readily available. Almost all (99%) tune in regular (NTSC) broadcasts but do not have built in HDTV tuners. They would require the same set top box you would buy to use with an older TV set. Set top boxes are in the $500. price range.
Less than ten percent of broadcasting is available (as simulcasting on the station's digital assigned channel) as HDTV. HBO has some HDTV offerings on cable while for the most part cable companies refuse to carry both the digital and analog signals of any given station.
There is a growing concern by movie producers that HDTV will lead to more copying and piracy of movies and shows. There is some lobbying to allow scrambling of broadcast signals which would make today's set top boxes unable to receive HDTV although they could still receive a 480i or 480p simulcast within the same digital channel.
HDTV vs. DTV vs, SDTV
DTV stands for "digital television". All of the U.S. HDTV formats are digital. Along with the HDTV formats are a number of lower definition DTV formats including "480p" which has the same number of scan lines making up the picture as NTSC. The 480p format is not high definition. The term SDTV for "standard definition television" has been invented to collectively represent NTSC, PAL, and other analog and digital formats with comparable resolution.
Smoother Diagonals (2/99)
Even if the resolution is reduced for the reasons described on this page, the 1920 x 1080 pixel format can reproduce diagonal lines and edges much more smoothly and clearly.
For 1080i there are 1920 pixel positions across by 1080 pixel positions vertically to choose from, compared with 720 pixels across by 480 pixels vertically for ordinary NTSC DVD.
Consider a thin diagonal white line on a black background. If the white line in the subject matter crossed a scan line directly over a pixel position, one pixel is white. But if it crosses between two pixel positions, it is usually reproduced as two light gray pixels. For regular DVD, two pixels side by side represent 1/350 the screen width. For 1080i HDTV, two pixels side by side represent 1/1000 the screen width.
If an HDTV set could produce a spot no smaller than 1/1000 the screen width, it could in 1080i HDTV produce a consistently smooth nearly upright white diagonal line of that width. In a 480p picture the thinnest nearly upright diagonal line would be 1/720 the screen width but would have some gray spots a little wider.
HDTV to NTSC Converter Boxes (set top boxes) (1/99)
The standard mass marketed HDTV to NTSC converter (set top box) is meant for playing HDTV broadcasts on any old TV set so it is constrained to work with the 525 line interlaced video frame. (Of the 525 scan lines, 480 of them hold the picture.)
There may be special purpose HDTV converters for data grade monitors with 600, 720, 1000 etc. scan lines but since they won't be mass produced, they will likely be much more expensive.
A top of the line HDTV to analog TV converter will deliver video for a picture better than just about any standard TV can display. There will be dumbed down quality skimping converters that don't.
A top of the line HDTV converter box will handle all 18 or so HDTV and DTV formats. A lesser grade box may handle only the three common formats 1920 x 1080, 1280 x 720, and 640 x 480.
For vertical resolution the converter box will reprocess the 16:9 aspect ratio HDTV picture with 1080 or however many scan lines to become a 360 scan line picture plus two 60 line black letterbox bars (total 480 scan lines), or to become a 480 scan line 4:3 aspect ratio picture with the sides cut off. A few converters will output a 480 scan line 16:9 picture for TV sets with adjustable aspect ratio. Exactly how the reprocessing takes place -- omitting scan lines, blending scan lines -- may vary depending on the make and model of converter. The vertical resolution cannot be improved further on a standard TV.
For horizontal resolution the converter box will convert the 1920 or however many pixels on a scan line into an analog signal. Theoretically a standard TV with, say, 650 lines of horizontal resolution can outdo a TV with 500 lines. Already I am told that many less expensive DVD players don't deliver all 720 pixels of horizontal detail, 640 is a commonly mentioned figure. So I would not be surprised if not more than 640 pixels' (480 lines on a 4;3 screen) worth of horizontal detail come out of lower priced HDTV converter boxes. Then a TV with 650 lines of resolution won't noticeably outdo the TV with 500 lines.
Pixels don't have to be square; horizontal resolution does not have to stop at the same number that vertical resolution has, and it may be much less such as on VHS tape. On an analog TV the aspect ratio does not change and the picture does not distort as the number of pixels horizontally in the video signal is varied. In my opinion the picture gets better and sharper up until the horizontal resolution is 1-1/2 times the vertical resolution, then further improvement is too hard to notice. (On a 4:3 screen 640 pixels wide by 480 high is 480 lines horizontally; 720 x 480 is DVD maximum capability, while 960 x 480 is horizontal resolution twice the vertical. I project that no manufacturer is going to offer reasonably priced HDTV to NTSC converters that give more than 720 pixels across.)
The more horizontal detail, the higher the frequencies needed to convey it as analog from converter box to TV. Longer or lesser grade cables tend to lose higher frequencies so if you know your converter is delivering upwards of 400 lines of horizontal resolution and you know that your TV set can reproduce upwards of 400 lies of resolution, you may well have to buy top grade cables and keep them short to avoid losing it.
The same rule for connections, component video is better than S-video is better than composite video, applies.
When you specifically look for horizontal resolution better than about 400 lines, it is extremely difficult to see and verify except with a resolution test pattern. Dot pitch and convergence are additional resolution limiting factors in a TV set
Details and Choices
HDTV is expected to have twice the detail from top to bottom, or picture quality equal to two of today's screens stacked. HDTV is expected to have twice the detail from side to side, and the picture is wider, so the quality should equal three of today's screens side by side. You may have seen those arrays of screens called "video walls" in department stores. They could be but are not a good demonstration of HDTV because there is no HDTV program material for them.
HDTV will let a station broadcast one extra high quality picture, or several separate camera angles equal to today's pictures.
The Choices For You, the Viewer
1. With your existing TV set
1A. Between now and the year 2002 (maybe a few years more), you may continue to watch the channels you are familiar with. No extra electronic equipment is needed.
1B. You may buy a converter box to view the new HDTV channels. It is connected between the antenna and the TV as you would connect the box from your cable company. If you have a VCR connected to the same TV, the HDTV converter box goes between the antenna and the VCR. Depending on the quality and complexity (and cost) of the converter, the following choices may be available.
1B1. When the TV station is broadcasting one HDTV picture, you can see it on your screen with no less quality than today's TV pictures, except the far sides of the picture may spill outside the boundaries of the screen and will therefore not be visible.
1B2. When the TV station is broadcasting one HDTV picture, you can see it on your screen with no less quality than today's "letterboxed" movies. That is, the picture may be zoomed out a bit so the complete width fits in the screen and the extreme top and bottom edges of the screen are left blank and (usually) black.
1B3. When the TV station is broadcasting several (up to six) different views or programs, you can choose any one to fit on your screen with quality about equal to today's TV pictures.
1B4. When the TV station is broadcasting several different views or programs, you can see several of them at once on your screen with about the same quality as a store surveillance TV screen split up into several views.
2. With a new HDTV set
2A. Caution: Most wide screen TV sets made before 1998 and sold in the U.S.A. are not HDTV sets. If you have one of these, see part 1 above. For a few models, the manufacturers have promised to make available a converter unit or card (not the same as 1B above) specific for that make and model and which will allow true HDTV reception as 2B through 2E below.
2B. On some models you can view existing TV channels with about the same quality as seen on today's TV sets.
2C. When the TV station is broadcasting one HDTV picture, you will see it with full HDTV quality subject to the quality of the TV set.
2D. When the TV station is broadcasting several different views or programs, you can choose one to fit on your screen with about equal quality as today's TV pictures.
2E. When the TV station is broadcasting several different views or programs, you can see them all on your screen, side by side and stacked, with all of the quality as they were broadcast with. This is about the same quality as today's TV pictures.
3. With your existing VCR
3A. You can continue to record and view programs from the channels you are familiar with.
3B. You can record and view HDTV programs provided you have an HDTV converter box. What you see on the screen is what you record. See 1B and 2B above.
4. HDTV on Cable (or Satellite) TV Channels
4A. You will continue to be able to view cable channels on your existing TV set as you do today, except that gradually stations will disappear from some of the channels. This is because the cable company inserted HDTV stations in some of the channel positions and the HDTV signal cannot be received by your existing TV and existing cable converter box.
4B. At some point your cable company will (or if you own it you will have to) replace the cable converter box with a new one. If you are still using your old TV set, you will definitely need an HDTV converter box (see 1B above). The HDTV converter box is connected between the cable converter box and the TV.
4C. If you bought a new HDTV set before the cable converter box was replaced, you will view the cable channels still in the old format with the same quality as 1A above. We are not sure whether those cable channels that now have HDTV programs on them will be received correctly on an HDTV set while using the old cable box.
4D. If you connected the cable directly to the TV set without a cable converter box, unscrambled channels, both HDTV and NTSC, should come out on an HDTV set. Since more and more channels are scrambled these days, you will want to change over to a cable converter box.
5. HDTV Video Disks and Tapes - Our Projections
5A. VHS tapes, 12" laser disks, and DVD's for HDTV will outwardly look the same as those in use today. You will have to read the label on each to tell the difference. You will need a new player to play the HDTV formatted ones. Rumor (2/99) has it that 12" laser disks will not be pressed with HDTV programs; if so they won't play on current LD players; also the DVD format will have taken over. A new digital format using VHS cassettes may include HDTV programs. The digital VHS cassettes will not play on a regular analog VHS VCR.
5B. Some new disk players and VCRs will work with older TV sets directly, some will need an HDTV converter box (see 1B).
5C. The playing time of each disk or tape will probably be shorter. The only consequence is that more disks or tapes will come in a boxed set for a given movie compared with today.
5D. We are not sure whether European HDTV will have the same format as U.S.A. HDTV. There are three "current" recording formats for both laser disks and VHS tapes: NTSC in the U.S.A. and Japan, and PAL and SECAM in Europe. HDTV in Japan is not the same as HDTV in the U.S.A.
HDTV Choices For the TV Broadcast Stations
6A. The HDTV channel can be used to broadcast the same program as the older NTSC channel.
6B. The HDTV channel can be used to broadcast a different program from the older NTSC channel.
6C. The HDTV channel can be used to broadcast up to six separate programs, which may or may not be related. For sports broadcasts, it will be possible to show several camera views at the same time. For special events, it would be possible to show regular programming in part of the screen rather than preempt it. One of the programs may be but is not required to be the same as the program on the older NTSC channel.
6D. After the year 2002 (or maybe a few years later instead) all broadcast stations must stop broadcasting on their older (today's) NTSC channels and the FCC will give the frequency bands out to other media or communications companies.
There are several aspect ratios (width to height ratios) used in filming movies. Obviously only one aspect ratio will fit the screen exactly. All others will leave dark borders either at the top and bottom, or on the sides. For HDTV, the aspect ratio of the screen is 1.77 to 1, or 16 to 9. Today's TV screen has a 1.33 to 1, or 4 to 3, aspect ratio.
The first movies were shot with the 1.33 to 1 aspect ratio and a few movies today are still shot this way. The widest reasonably common aspect ratio is 2.35 to 1. The most common aspect ratios in full length movies are 1.85 to 1 and 2 to 1. Sometimes the movie is filmed with a smaller aspect ratio and the top and bottom edges are covered up (matted) for theater projection and uncovered for video copies and TV broadcast.
HDTV promises less obtrusive scan lines (because there are more of them), less flicker, and less smearing of colors. But actual improved sharpness will vary widely depending on the program material.
As any photographer knows, fast shutter speeds are needed to get sharp pictures of moving objects. Small lens openings are needed to have both near and far objects in focus at the same time (if that is what the photographer or movie director wanted). This can all be achieved together only outdoors in sunlight. In practice, individual movie film frames are quite blurred much of the time. You can see this blurring easily by still framing your VCR with just about any program.
Therefore do not expect HDTV to give you very many super sharp still frames. And some of the time an HDTV picture won't look that much sharper than today's TV picture.
Be Careful Buying High Definition (HDTV) TV Set
In a Nutshell:
Some TV sets for HDTV won't give a high definition picture. Here are a few reasons and things to look out for when buying:Not enough scan lines
Too coarse dot pitch
Electron beam too fat
Convergence (registration) errorsAn HDTV converter box (decoder) connected to a top notch standard TV may well produce a picture as good as a low end HDTV set.
Being able to view true HDTV will depend on manufacturing TV sets with the same quality and capability as is already the case with computer monitors.
The first HDTV sets may have reception problems because the design engineers don't have enough HDTV programs to do testing and verification with.
We expect that true HDTV sets will take longer to come down in price once HDTV catches on.
Not Enough Scan Lines
There are two proposed primary high definition modes, 1920 pixels wide by 1080 scan lines high, and 1280 by 720. Both of these are intended for a 16:9 aspect ratio screen.
Already some "HDTV ready" TV sets are planned to arrive on the market soon and they don't have 720 scan lines let alone 1080.
Quoting from an internet forum on video (Oct. 98),
"In the race to display 1080i sets like the new Toshibas TP61H95 & TW65H80 cannot display 720p. They are built with 560 lines and a line doubler. There are no guarantees 1080i will be the HDTV standard. All who are shopping should keep this in mind when falling in love with the idea of the maximum lines of resolution."
(http://www.digitaltheater.com/bb/Forum2/HTML/001051.html)
(subject to availability)
It is easy to take the 1080 line interlaced HDTV image and treat the even and odd fields each as complete 540 line frames. This cuts the vertical resolution in half. Many years ago, a common defect of TV sets was putting the even lines on top of the odd lines (line pairing) instead of correctly interlacing them.
To display a 720 scan line picture using 560 scan lines, scan conversion is needed. Generally speaking this involves blending of two lines into one here and there or repeating a line here and there. (The technical terms are "resampling" and "interpolating".) There is significant quality loss.
Note that a 1280 pixel wide by 1024 pixel high resolution monitor is still insufficient to reproduce the 1080 line HDTV picture. Either conversion from 1080 to 1024 lines has to be done, or the edges of the picture have to be cropped, losing 28 lines off the top and 28 lines off the bottom.
From my examination of computer monitors currently available, displaying and resolving all 1080 scan lines of HDTV pictures is not technically difficult today.
Electron Beam Too Fat
Home grade CRT based projection TV's (both RPTV and FPTV) have tubes with screens usually between 5 and 9 inches. Too fat an electron beam spot is more of a problem with projection TV's than direct view tube TV's. No matter how finely the electron beam is focused, the electrons, like light rays, scatter a bit when they hit the screen. But I have seen NTSC projection TV's where dark gaps on both sides of every scan line were visible. This is enough to prove that with quality components, the electron beam is fine enough for HDTV, which has about twice as many scan lines. For projection TV sets, the smaller projection tubes (5 inch) cannot resolve all 1080 lines for HDTV.
Convergence Errors
Convergence must be improved in the mass production of TV sets in order for HDTV to deliver its much superior picture.
A typical large screen TV set seen in the average store is likely to have noticeable convergence error of the red, green, and blue electron beams even for an NTSC program. A one fifth of one percent error, quite common near the edges of a direct view screen, equals a one scan line displacement for NTSC. The "average" projection TV sets I see often showed blurred text and noticeable color fringes around objects due to misconvergence, which I estimate as being at least two NTSC scan lines' worth of displacement in some places on the screen. Misconvergence this large is enough to disqualify the HDTV picture from being high definition.
If HDTV sets can be consistently manufactured with at most one HDTV scan line convergence error, that is certainly improvement over a standard TV having one NTSC scan line convergence error.
Although convergence is roughly correct for each picture tube as it is manufactured, the final step in convergence is a manual trial and error process. Traditionally convergence is done by a serviceman who places permanent magnets on the picture tube neck and elsewhere, and rubber shims to hold parts in position. The more upscale TV sets have electromagnets on the tube neck that are controlled by a microprocessor. For these sets the viewer can adjust the convergence from the remote control and doing so stores appropriate data for the microprocessor. Then, during viewing, the microprocessor manipulates the electromagnets for every sweep of the electron beam across the screen so as to simulate permanent magnets on the picture tube neck.. For converging of inexpensive TV sets white spots are placed on about ten to twenty reference points on the screen, some in the center, some near the edges, and some in between. Mid-grade NTSC TV sets are converged with 49 points (a 7 x 7 grid of small spots) and the top of the line TV sets and HDTV sets have 100 or more points. The best that can be done is to line up the electron beams on each of these spots and hope that the electron beam does not stray between the spots.. Some manufacturers may reserve the better tubes, with no more than one scan line's uncorrectable offset between the reference points, for the top of the line TV sets.
Computer Screens and Dot Pitch
We combined the subtopics of computer monitors and dot pitch because one of the major differences between computer screens and TV screens is dot pitch. If you have viewed a computer screen and a TV screen side by side, you undoubtedly noticed that the TV picture is more coarse or grainy.
The typical dot pitch for a medium sized (20 inch) TV picture tube is about 0.8 millimeter. For a large screen (32 inches or more) the dot pitch may be larger, certainly not smaller. Today's computer monitors can give a much sharper picture than a standard TV set twice the width because of the much finer dot pitch.
The dot pitch is usually 0.28 mm or less for a good computer monitor. The good computer screens I have seen also have better convergence, displacement no more than one out of 1000 scan lines for the computer monitor vs. one out of 500 (480) scan lines for the TV. The disadvantage so far is that the largest commonly available computer monitor screen is 20 inches.
We believe that to acceptably resolve fine luminance detail such as a white picket fence in the background, each detail element must span at least two of the three colors (red, green, blue) in a stripe group or dot cluster. At this level of detail there will be some discoloration, the white elements would be magenta, cyan, or yellow depending on which two color phosphors they happened to line up with. At normal viewing distances, the human eye might not notice the rainbowy overall effect.
For example, take a 35 inch stripe phosphor TV tube with 0.8 mm dot pitch, there would be 2670 individual red green blue vertical stripes across the screen. (The screen width is 28 inches, times 25.4 mm per inch times three primary colors divided by 0.8 mm). Taking the stripes two at a time, we have 1335 pairs, allowing 1335 pixels each spanning at least two primary colors. This is a best case; if the dot pitch were 1.0 mm instead of 0.8, there would be only 1070 paired stripes across which would deliver about half the luminance resolution of the ultimate HDTV picture.
A 14 inch (small but still common) .28 mm dot pitch computer screen can resolve all 720 pixels across and all 480 pixels high for DVD. A 21 inch .28mm computer screen can almost display the full capability of HDTV. (Additional electronics not already in computer monitors is needed to accomplish both of these.) Although I haven't seen it, I would expect the 21 inch monitor to resolve 1600 pixels across with no more than one pixel's convergence error anywhere on the screen. This will give a very good although small (20 inch) 1080 interlaced scan line HDTV picture with no resampling, interpolation, or scan conversion artifacts.
The requirement for color resolution is half the luminance resolution, so for 1920 pixel wide by 1080 scan line high HDTV, 960 pixels horizontally are needed. For the 35 inch 0.8 mm pitch TV example, the 2670 color stripes represent 890 triplets, enough to let the 960 pixels each span two of the phosphor colors and most of the third. Unfortunately most 35" screens today have dot pitch more than 1.3 mm rather than 0.8 mm.
Today you have to pay about $2000. for a 21" monitor alone, without tuner, audio, non-interpolative scan conversion, and other non-computer related video electronics. A computer monitor has easily adjusted height and width controls, may be able to remember the aspect ratios for 1080i vs. 720p HDTV and 480i NTSC, but you will have to manually change the settings when switching between computer and TV use.
Signal Consistency Problems
It is possible that the first HDTV sets might not receive all formats of HDTV broadcasts and programs. Since there are few HDTV broadcasts, none in most areas, the design, building, and manufacturing of the sets do not have programs to conduct testing with. The sets will perform correctly with laboratory generated programs but some actual broadcasts that don't quite adhere to the specifications might not be received well.
Who is Buying What? (10/98)
The Tightwad
Will buy an HDTV converter box only when the number of NTSC stations dwindles significantly (maybe 4 years from now). If the TV needs replacing, will buy another standard TV.
The Late Bloomer
Will either continue to use present TV or upgrade to another standard TV. Will buy a converter box two, maybe three, years from now to watch HDTV programs. Around the time NTSC goes away (ca. 2006 and HDTV has been around for a long while) will buy an HDTV set.
Middle of the Crowd
If the present TV is near top of the line, will keep it a few more years. If it is quite basic, will upgrade to another standard TV. Will buy converter box fairly soon. Will buy HDTV set maybe three or four years from now, when prices have dropped somewhat but still could go lower later.
First on the Block
Will buy HDTV set almost as soon as it comes on the market. Will upgrade it before NTSC goes away (ca. 2006).
Allan W. Jayne, Jr. -- P.O. Box 762, Nashua, NH 03061
603-889-1111 -- ajaynejr@aol.com
If you would like to contribute an idea for our web page, please send
us an e-mail. Sorry, but due to the volume of e-mail we cannot reply personally
to all inquiries.