Television
HDTV High Definition
Television |
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HDTV (high definition television) is the new
standard in television technology. HDTV signals are transmitted
digitally and provide wide-screen, high resolution picture quality
along with multi-channel CD sound quality.
What is DTV? What is Digital Television?
The change to DTV is even more significant than the
change from black-and-white TV to color TV which occurred in the
1960s. DTV is more than just a new kind of TV set, and more than
just high definition (HDTV) programs. DTV is a new way to broadcast
and receive TV that gives you a better picture, better sound and
more choices than ever before.
Depending on what you ’re watching and what kind of
equipment you have, digital television may enhance your viewing
experience in any number of ways. You may see movies or sports in
stunning HDTV resolution on a 16:9 wide-screen with Dolby Digital
sound. Every DTV program you watch will have DVD-quality pictures
without any snow, ghosts or static. Some programs may offer multiple
audio tracks, and some TV stations may offer up to four programs on
a single channel. And others will give you access to interactive
content, for learning more about your TV show, shopping online and
more. The possibilities are endless.
What do you need to know about
DTV?
How you receive DTV and HDTV
broadcasts; How to choose a digital television
set; What the FCC has to say about DTV.
The
good news is DTV is somewhat affordable today, certainly available
and easier to understand than you ever thought
possible.
First, let's examine some misconceptions about
HDTV.
Digital Cable is the Same As
DTV. This is NOT true.
Digital Cable is
certainly digital, meaning it is transmitted as ones and zeros, but
that does not make it DTV or HDTV. It is true that you can get DTV
from a Digital Cable subscription, but just because you are getting
Digital Cable does not necessarily mean you are getting DTV or HDTV
signals.
DTV is the Same As HDTV. This is
NOT true.
Digital Television, DTV, is an umbrella term
used for a set of 18 different formats for broadcasting television
in a digital format put out by the ATSC. High Definition Television,
HDTV, is six of those 18 DTV formats that has a resolution of at
least 720p and has an aspect ratio of 16x9.
All
Television Will Be HDTV by 2006. This is NOT
true.
The Federal Communications Commission or FCC has
mandated that by 2006 all broadcasters must broadcast DTV signals.
This pertains to Over The Air transmissions since this domain
is regulated by the FCC, and does not pertain to DTV through Cable
TV or Satellite TV companies.
HDTV takes up a lot of
bandwidth and it is up to the Cable and Satellite companies to move
from sending you analog signals to DTV signals. To remain
competitive the Cable TV and Satellite TV companies will offer
upgraded services as market demand occurs. This will mean that they
too will offer HDTV content even though the FCC mandate does not
affect their domain.
This also means that broadcasters
can send DTV signals that are of lower resolution than that of true
HDTV. All the OTA broadcaster must do is meet the minimum
requirement of the FCC to broadcast digital signals. This does not
mean they have to broadcast HDTV.
More questions about
HDTV answered.
What is
HDTV?
High-definition television is a format for
broadcasting TV programming. The 50 year old format is called NTSC
(National Television Standards Committee) and is analog. By
contrast, the signals in HDTV are digital and the format is
called ATSC.
Do I need a new television set to watch
HDTV?
The simple answer is Yes. You must have a
high-definition tuner and monitor to properly decode HDTV signals
and display them accurately. Your old analog NTSC television
set simply ignores HDTV signals that are being broadcast. When you
want to step up to watching HDTV, you'll need to get a new high-def
TV set.
What's different about HDTV versus the old analog
signals?
The HDTV signal is digital, resulting in crystal
clear, noise-free pictures and CD quality sound. You'll get a much
better picture and much better sound.
HDTV has many
benefits.
Benefit: Aspect Ratio Most analog
signal televisions are manufactured in a 4 by 3 aspect ratio, which
means the screen is 4 units wide by 3 units high. But theatrically
released movies are usually in a much wider aspect, taking advantage
of the human field of vision (which is wider across horizontally).
HDTV signals are sent in a 16 by 9 aspect ratio, more like the wide
scope of movies. HDTV's aspect ratio makes for a more realistic
viewing experience.
Benefit: Picture
Resolution Resolution is a measure of picture sharpness.
Analog television contains about 480 active scanning lines resulting
in a picture resolution of about 330 lines of resolution. By
comparison a VHS VCR has about 240 lines of resolution which is why
VHS recordings don't look as sharp as the original picture. DVD's
offer higher resolution typically on the order of 480 lines of
resolution. HDTV offers resolution that is at least twice that of
analog television. You can expect razor sharp images from
HDTV.
I have heard that there are two HDTV formats — 720p and
1080i. Is there a difference between these formats and can my
television receive both these formats?
Regardless of the HDTV
format being broadcast, all new HDTV receivers can receive both
formats. HDTV televisions will convert any received signal to a
format that is compatible with your display. The 720p format uses
progressive scanning, which is just like your computer monitor.
Progressive scan offers crystal clear images that virtually
eliminates those scanning lines that are visible on most large
screen televisions.
The 1080i format uses interlace scanning.
Scanning lines are less visible on big screens due to the number of
lines.
Benefit: Digital Sound Just as your CDs
sound better than your old audio cassette tapes, HDTV's digital
audio signal sounds better than standard television's analog sound.
Also, some HDTV programs include Dolby Digital 5.1 surround sound.
Properly decoded, each audio track can be sent to a different
speaker, creating a three-dimensional sound field in your living
room.
What do I need to receive HDTV?
In
many areas, HDTV is only available as an over-the-air broadcast
signal. This requires the use, in most cases, of an outdoor antenna
pointed in the direction of the broadcaster's tower. You will also
need a new HDTV receiver that can decode the digital signals. HDTV
channels are typically different than your cable or over-the-air
channel.
Is HDTV replacing standard
television?
Eventually that is the hope, but not
immediately. Broadcasters will continue to offer programs in the
standard format for a few years.
Why Switch to DTV?
What excites people most about DTV is its brilliant
picture quality. There are several reasons why DTV images are so
much crisper and clearer:
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DTV broadcasts are fully digital, so there ’s never
any analog interference such as static, snow or ghosting like you
get with analog TV transmissions.
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DTV images are often comprised of many more pixels,
or picture elements, than analog images. This higher resolution
creates sharper, more precise images.
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Many DTV programs are “progressive scan ”(as denoted
by the “P ”in 480P).This means that every pixel on the screen is
refreshed simultaneously, for a flicker-free image. Progressive
scan makes text more legible and fast-motion video smoother than
on analog TVs with “interlaced ”scan. Interlaced scanning (e.g.,
the “i ”in 480i) involves refreshing pixels in alternation –first
the odd lines, then the even lines. As a result, only half of the
pixels on screen are “active ”at any given moment.
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Digital TV sets are capable of displaying the true
digital picture and sound without down-converting the signal as
analog TVs do. Digital TV sets are even capable of making most
analog signals look better, by doubling the lines of resolution to
a progressive scan image, and through the use of digital filters
that remove the unwanted artifacts that can degrade an image.
DTV, SDTV, HDTV-- What does it all mean?
DTV is actually an umbrella term that describes any TV
signal that is digital. There are two main types of DTV that you
need to know –standard definition (SDTV) and high definition (HDTV).
The main difference between them is that HDTV has many more pixels
and much greater resolution.
HDTV is the most robust and detailed TV image you can
have. It ’s even sharper than a DVD. Depending on the format, an
HDTV image can have more than 1,000,000 active pixels. HDTV has a
minimum resolution of 1280 x 720 pixels progressive scan (720P) or
1920 x 1080 pixels interlaced (1080i).
Standard definition TV can have either the same
resolution (about 150,000 active pixels) or double the resolution of
analog TV, depending on whether it is presented as interlaced (same)
or progressive (double) scan. But SDTV outshines analog TV because
it is not prone to static, snow and ghosts the way analog is. SDTV
can also be either 4:3 standard aspect ratio or 16:9
wide-screen.
When will the switch to Digital Television
occur?
It is already happening and will be phased in
gradually over the next few years.
The FCC (Federal Communications Commission) has
mandated that all TV broadcasts must be in Digital format by the
year 2006.
Broadcasters who begin DTV transmissions, will simultaneously
broadcast analog TV as well.
Also take note that these mandates have not stated anything about
cable broadcasts and/or high definition broadcasts. It is up to the
cable companies to make the switch to digital on their own. As for
the actual TV stations, they are only required to broadcast in a
digital format and broadcasting in high definition is completely up
to them.
How do I get DTV?
Getting digital TV is easy. There are three things
that you need to view true, all-digital DTV: First,
you need a digital source such as over-the-air broadcast, digital
satellite or true digital cable. Second, you need a set-top
box or built-in tuner to receive, tune and decode the digital
signal. Third, you need a digital TV to display the brilliant
digital picture and sound.
The good news is you don’t have to upgrade to DTV all
at once. You can view a DTV source on an analog TV by connecting a
digital set-top box (tuner). Or you can get a DTV set, which
will give you the most from every source you watch – then add a
set-top box and digital source later. If you have a progressive scan
DVD player, you’ll immediately notice the difference that DTV
makes.
What about the new digital TV sets, what kind of
digital TV sets are available and what are the new TV display
technologies?
The new digital super-thin flat screen TV
displays are impressive. Very large screen sizes are possible. Some
can be hung on your wall. Two of the more popular TV display
technologies are Plasma
and LCD. See Plasma
vs. LCD for an explanation of the advantages and disadvantages
of each. Another popular technology is DLP.
There
are a lot of choices but don't feel bad about not knowing which to
buy. Even the big world-wide electronics manufacturers cannot agree
on which display technology is best or which one will ultimately
prevail in the marketplace. Sony has said they think LCD is the way
to go, even though they also make Plasma displays. Panasonic has
said they think Plasma is the way to go even though they also sell
LCD displays. See TV displays for more.
HDTV is part of several standards incorporated in
digital television or DTV. Basically, DTV is composed
of three separate standards:
- HDTV 1080 (1080 lines of
resolution, 16:9 aspect ratio)
- HDTV 720 (720 lines of
resolution, 16:9 aspect ratio)
- SDTV (480 lines of resolution,
16:9 or 4:3 aspect ratio)
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Although the ATSC
defines both 1080 lines and 720 lines as HDTV, there are
differing views with respect to how HDTV should be
defined. |
United
States major market television stations began
transmitting DTV in the fall of 1998. The number of new
DTV stations on
the air is increasing every
month.
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HDTV is the biggest breakthrough in broadcasting since
color TV. It offers wider pictures with greater detail and the
clarity of motion pictures. Compared to standard television
(NTSC), the true HDTV image has twice the luminance
definition - vertically and horizontally - and is twenty-five
percent wider. Standard television aspect ratio is 4:3 (four
units wide, three units high) - the HDTV aspect ratio is 16:9.
The 16:9 ratio is much closer to the average wide-screen image
shown in movie theaters. The biggest difference, and the
greatest appeal of HDTV, is its clarity.
True HDTV pictures are composed of 1080 active
lines (1125 total) whereas current standard television
pictures are composed of only 486 active lines (525 total).
While it is possible to see the lines that make up standard
television pictures, HDTV lines are not at all noticeable. The
fine-grained HD picture contains five times more information
than does the standard television picture and is accompanied
by multi-channel, CD quality sound. The difference in video
and sound quality is dramatic.
What shows can I see
right now in High Definition HDTV?
Over 1,000 TV
stations now broadcast digital signals in over 200 markets
which cover 95% of U.S. TV households.
Sports
broadcasts offer compelling content for high definition TV.
The Super Bowl, NFL playoffs, and NBA playoffs were broadcast in high
definition. Events that will be broadcast in HDTV include the
NCAA Final Four, the
NHL All-Star Game, the
Masters Tournament,
and Monday Night
Football to name a few.
Off-Air HDTV
Programming
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CBS broadcasts most of its primetime
programming in high definition. Among the series
available in HDTV are:
JAG, CSI, Judging Amy, The Agency,
Hack, The Guardian, Presidio Med, The Fugitive, Becker,
Touched by an Angel, Still Standing, Everybody Loves
Raymond, Yes Dear, King of Queens, and The Young and the
Restless. |
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ABC offers NYPD
Blue, Alias, The Practice, According to Jim, My Wife and
Kids, Who Wants to Be a Millionaire, George Lopez,
Married to the Kellys, Life with Bonnie, The Wonderful
World of Disney and a much larger selection
of feature films every month. |
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NBC broadcasts The
Tonight Show, ER, American Dreams, Ed, Crossing Jordan, and Frasier. NBC executives have
stated a commitment to producing a more significant
portion of its primetime lineup in HD in the near
future. |
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FOX is working on
expanding broadcasts in HD. |
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Warner Brothers has dramatically
increased its level of HDTV programming. Series offered
in high definition include Reba, Everwood, Smallville, Angel,
Gilmore Girls, and What I Like About
You |
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From early on, PBS has supported HD
broadcasting and currently airs documentaries, specials, and performances via select
affiliates in many parts of the country.
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DIRECTV® HDTV
Programming
DIRECTV currently offers outstanding
high definition programming through its new DIRECTV® HD
PACKAGE, which includes ESPN HD, Discovery HD Theater,
HDNet, HDNet Movies, as well as through its premium
programming packages HBO and SHOWTIME. DIRECTV plans
to aggressively continue its HD programming expansion.
The HD Package includes:
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ESPN HD Sports events, news,
information and entertainment, including ESPN games from
MLB, NBA, NFL and NHL. |
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Discovery HD Theater Programs
about nature, travel,
geography, world culture, science & technology
and more. |
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HDNet A 24-hour network
featuring live sports like
NHL® and MLS®
games, boxing, drama series, concerts and original news and documentary programming including
HDNet World Report and Across America. |
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HDNet Movies Delivers a
24-hour schedule of blockbuster movie
titles from Warner Bros., Sony, and other major
studios, as well as made-for-TV movies,
independent films and shorts. |
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Channels 80,81 offer many of America's
favorite primetime original series. |
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HBO-HD® (DIRECTV channel 509)
is available as part of DIRECTV's HBO® premium
movie package. With over half of HBO movies broadcast in high
definition, there's no shortage of great entertainment. One of
HBO's most notable highlights are The
Sopranos, Sex in the
City and Six Feet
Under. |
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SHOWTIME-HD® (DIRECTV channel
543) The SHOWTIME HD Channel is broadcast from DIRECTV's
Satellite in the 110 degree orbital slot position. SHOWTIME
adheres to original aspect ratio in which movies were filmed
and was among the first to transmit Dolby Digital
5.1.
If you currently receive HD programming using an
18"x24" elliptical dish with dual LNBs, you will need to
upgrade to a triple-feed configuration by adding a Sat C kit
in order to receive the SHOWTIME HD Channel or purchase a
Triple LNB Dish. Showtime offers several popular original
series, including The Chris Isaak Show,
Queer As Folk, Jeremiah, and plans to offer Earthlings, Dead like Me, and
Out of
Order. |
About
HDTV
Index
Digital
and High-Definition-Television
The
Digital Difference
Resolution
Interlaced
and Progressive Scan
Progressive
Scan System
High-Definition-Television
- vs. - Standard Definition Television
Picture
Pixels
Why
Is "Wide-Screen" TV The DTV Standard?
Why
"Wide-Screen"?
ATSC
DTV Picture Formats (Compression Formats)
Digital
and High-Definition-Television
How does digital television (DTV) differ from the
traditional, analog TV, with which we all grew up? Most of us
have never questioned the technology hidden behind the TV
picture tube; nor given any thought to how our favorite TV
programs show up in our living rooms. Without getting into a
lot of "hi-tech-stuff," (at least we'll try not to) let's
start by looking at the TV set we've all been familiar with
for the past 50+ years.
The standard-analog or NTSC-TV, (National Television
Standards Committee) transmits only the video signal,
containing no other information. But a major problem with
analog signals is that between the transmitter and your TV set
many things can interfere, thus distorting the picture you
see. From a plane flying far overhead, to hilly terrain, tall
buildings and even atmospheric conditions, all are obstacles
that can interrupt the signal.
Also, the strength of the analog signal is critical; a
weaker signal can cause "snowy" and distorted pictures -
something with which those of us who remember
"pre-cable/satellite" are too familiar.
The Digital
Difference Goto Top
Digital TV signals are made up of coded instructions - the
same 'bits' of 'ones and zeros' that make your computer work,
and give life to your 'CD's' and 'DVD's' - which are
transmitted to your Digital Receiver, (aka: Tuner, Decoder or
Set-Top-Box "STB") which in turn deciphers the code.Your
receiver isn't concerned with the signal strength, or what
conditions exist between you and the transmitter. As long as
the signal gets to the receiver, it can read the code and
reproduce a near-perfect picture.
A distinct advantage of digital broadcasting is that bad
reception is a thing of the past. One reason Cable TV caught
on is because it delivers clear TV pictures without regard to
the viewer's location. Viewers don't have to be constantly
adjusting the antenna in an attempt to tune in a clear
picture.
DTV eliminates "snow" and "ghosting" caused by the weak
signals from distant or blocked transmitting towers. If your
analog television set is not receiving a strong, undistorted
signal from the tower, you will not get a perfectly clear
picture.
Both digital and analog television signals get weaker the
farther they travel away from the transmitting tower. On an
analog TV, the picture slowly deteriorates from bad to worse
for more distant receivers. However, the picture on a digital
set will stay perfect until the signal becomes too weak for
the receiver to distinguish between a (1) and a (0), at which
point the image disappears completely. You could compare this
to sending Morse Code. As long as the person at the other end
can make out the dots and dashes being transmitted they will
be able to read the message. Once they lose the distinction
between a dot and a dash they lose the message. Digital TV
acts the same way; instead of sending dots and dashes, it
sends millions of (1's) and (0's) every second. The bottom
line ... you either receive a 100% perfect quality image, or
nothing at all. What this means to you, the digital, or
high-definition-television viewer, is that you will never get
a "bad" picture. Either you have a picture or you don't.
However, if you are receiving over-the-air or "off-air" (OTA)
broadcasts, it is crucial for the antenna to be accurately
directed towards the signal source - the transmitting tower of
the station you are watching.
In High-Definition-Television, the picture displayed on
your television screen is digitally transmitted, but it must
also meet the "ATSC" (Advanced Television Standards Committee)
'Standards for High-Definition-Television' in order for it to
be "true" HDTV. The image you see on your television screen is
comprised of a series of horizontal lines. An electron gun
'shoots' energy beams (light) which strike a layer of phosphor
on the inside surface of the picture tube, causing it to glow.
These glowing lines create the image displayed on your TV
screen. How they are formatted, which resolution is used, what
standards are met, determine the type of television picture
you are receiving.
Resolution
Goto Top
Basically, TV 'resolution' refers to how many horizontal
lines are displayed on your TV screen. (Although it is the
horizontal lines that are counted, this is usually referred to
as "vertical resolution" because the lines are counted from
top to bottom - or vertically).
Note: Resolution is sometimes expressed as the total
'pixel' count, which is a product of the number of lines and
number of pixels per line.
Interlaced and
Progressive Scan
There are two methods that can be used to display the lines
on the screen - either "Interlaced" or "Progressive Scan." The
NTSC adopted the standard known as "interlaced" to provide a
method of compression that achieves a higher resolution using
less-costly circuitry. The NTSC-analog standard is "525 lines
- interlaced, at 30 fps" (frames per second). This may be
written as: 525-i/30 fps; however, only 480 lines are used to
make the visible image, the remaining lines contain
information pertaining to picture synchronization and are not
seen. For this reason, the stated 'resolution' usually refers
only to the visible lines; ie... 480-i/30 fps. In using the
"Interlaced" method, the 480 lines are created in two fields
(phases). The "scan-rate" for these (2) fields is 60hz (60
times per second). In phase #1, the first 1/60th of a second,
240 lines (the odd numbered lines - 1,3,5 etc) are scanned on
the tube. In the second 1/60th of a second, (phase #2)- the
remaining 240 (even-numbered) lines are scanned. Thus each
field of 240 lines is scanned 30 times a second, and produces
one complete frame (30) times per second; (1/60 second X 2
fields = 2/60 second = 1 complete frame, 30 times per second).
It's the total lines-per-image that indicates the resolution
of the system, ie. (525i or 480i).
There are other analog systems that have resolutions of
less than 480 lines per image. For instance, DVD's have 450
lines; while VHS players come in with a poor showing of only
240 lines.
Progressive Scan
System Goto Top
Digital TV has formats that use the interlaced system;
however, DTV also uses another system, called "Progressive
Scan." The progressive system scans the total number of lines,
60 times a second; not half and half as in interlaced. This
means you see the complete image displayed on your TV screen
two-times more often. This results in smoother motion in
moving images, having less motion artifacts and none of the
visible "flicker." A progressive scan system with 480 lines of
resolution is written, "480p."
High-Definition-Television
- vs. - Standard Definition Television
The ATSC has assigned (18) formats to Digital TV. At the
current time, in HDTV we are primarily concerned with just
two: 1080-i and 720-p. "True" High-Definition-Television may
have, either 1080 interlaced lines, or 720 progressive-scanned
lines. (Higher resolutions may be introduced in the future;
for instance 1080-p, which is not currently used because of
high manufacturing costs).
Digital broadcasts in 480-i or 480-p are classified as
"SDTV" (Standard Definition). SDTV has a sharper, crisper
picture than NTSC-analog TV. It is superior to analog because
the transmitted signal is digital. SDTV can be either (480i)
or (480p) but is more often 480p. On smaller (direct-view) TV
sets, 480p is noticeably better than the analog 480-i, but on
the much larger, "projection" sets, SDTV can not compare to
High-Definition-Television's 720p, or 1080i formats.
Note: 1080i displays more lines and thus delivers more
information. This produces better "spatial resolution" -
producing sharper pictures when the image is "still" or has
little motion. Manufacturers have generally preferred the
Interlaced format because more lines of resolution can be
delivered with less bandwidth, resulting in lower
costs.
Many viewers, including those in the computer world, prefer
the 720p format because its full frame, progressive scanning,
enables it to reproduce fast-moving action and graphics
without blurring the image. Thus, 720p is said to have better
"temporal" resolution. Incidentally, if you have a computer
system - doesn't everyone? - your monitor uses progressive
scan.
Both sides in this (i/p) debate are dug-in, with ardent
supporters and aggressive detractors abounding on each side.
But which is the better system is a subjective determination.
You might say "it's in the eye of the beholder."
The different television networks have individually
selected the particular DTV format used by their respective
networks for transmitting High-Definition-Television
broadcasts.
For instance, ABC uses 720p, while
CBS transmits in 1080i. The important note for you, regardless
which High-Definition-Television System you buy, is to be sure
it is capable of "up-converting" or "down-converting,"
enabling you to view all transmitted signals in your set's
designated (native) format or native
resolution.
Picture
Pixels Goto Top
High-Definition-Television displays pictures that contain
significantly more detail, resulting in much 'crisper'
pictures. Images viewed on TV screens are made up of small
picture elements known as 'pixels.' Each of these pixels is
made up of three, closely spaced 'dots' of color - red, blue
and green.
Combined together on the TV's phosphor screen, and viewed
from a distance, the colors are seen as one. The phosphor at
each of these dots emits light directly proportional to the
intensity from the electron beam that hits it, as it scans
across the screen.
On traditional, NTSC TV's 256 levels of intensity are
possible for each of the three colors. The result is a range
of 16.8 million colors for each pixel. The pixels in the
analog system are slightly 'taller' than their width. Get up
close to an analog screen - especially the larger projection
sets - and you can easily see the red, blue and green
rectangles. This is why distortion is sometimes seen on
traditional, NTSC TV's.
The pixels in HDTV sets are square; they are also smaller,
and spaced closer together. There can be (4 1/2) HDTV pixels
in the same space that a single NTSC pixel requires. The
result is that High-Definition-Television can display at least
4.5 times more detail than NTSC-analog TV.
What
Is "Aspect Ratio"? Why Is "Wide-Screen" TV The DTV
Standard?
DTV sets are sold in two 'Aspect Ratios.' Aspect Ratio
refers to the ratio between the horizontal (width) measurement
and the vertical (height) measurement of the screen. This
ratio is also used in reference to how the picture is
transmitted and displayed on the screen. The two aspect ratios
used in DTV are (4:3) and (16:9). That is, (4) units wide by
(3) units high, and (16) units wide by (9) units high
respectively. Your NTSC-analog television has an aspect ratio
of (4:3); the screen appears almost 'square' because it has
just slightly more width than height. For instance, a (4')
wide screen would have a height of (3'). Digital Television's
(16:9) 'wide-screen' is approximately (1/3) larger than a
comparable (4:3) set. As a comparison - if you have a
"wide-screen' set measuring (16) units wide by (9) units high,
then a comparable (4:3) set would measure (12) units wide by
(9) units high. The ATSC adopted the 16:9 "wide-screen" aspect
ratio as the standard for Digital-HDTV, because significantly
more information can be displayed on the screen. And
Wide-screen DTV/HDTV sets appear more 'rectangular' than the
familiar 'square' shape of your NTSC-analog set.
Why
"Wide-Screen"?
Goto Top
Believe it or not,
the 4:3 aspect ratio was originally developed by W.K.L.
Dickson in 1889, while working at the famed Thomas Edison
Laboratory. He was running experiments with a Kinescope
(motion-picture) camera. He made the decision to create his
film (1") wide and (3/4") high. This ratio soon became the
standard of the film industry. In 1941, when the NTSC proposed
the standards for broadcast television they had no reason not
to adopt the same 4:3 ratio used by the film industry.
In the 1950's, Hollywood found they needed to provide the
public with a specific reason to buy movie tickets, when it
was easier for them to sit home and enjoy free television.
Besides trying innovations like "3-D", studios experimented
with the aspect ratio; "Cinemascope" was one of the early
'wide-screen' ratios that can still be seen today.
The reasoning that led to wide-screen formats is simply
that the wider view is closer to the human field of vision.
Because the viewer is visually drawn more into the action with
wide-screen, the enjoyment level is enhanced. Our vision is
optimized within a 30-degree field of vision. We see details
best within the 'center' area of this field, while our
peripheral vision is better at detecting motion. Beyond
30-degrees there is no visible benefit.
The familiar 4:3 ratio allows us only a 10-degree field of
vision. In the theater, 'wide-screen' formats were easy to
reproduce by using more or less of the area projected on the
screen, as needed. However, as movies were displayed on TV
screens, and later made into videos, the aspect ratio became
more complicated. Initially, movies were 'cropped' to 'fit'
4:3 analog-TV sets.
This is accomplished by a process called "pan and scan,"
which involves moving the 4:3 viewing area back and forth, to
center the scene on the primary action. While pan and scan is
okay if nothing is occurring in the peripheral areas, often,
important information in these areas is cut off. In addition,
pan and scan may not give the viewer the same "feel" that the
original film had, because the scene is not actually seen as
the movie director intended.
To enable movies to be viewed in their original,
'wide-screen' aspect, the "letter-box' process was developed.
With 'letter-boxing,' the picture's height is reduced, thus
allowing the full width of the image to fit the TV screen.
This enables you to see the entire scene the way it was
filmed.
However, reducing the image height requires removing some
information that leaves a portion of the vertical area 'blank'
- this appears as a black 'bar' on the screen. The image is
displayed in the center of the screen, with the blank area
divided into two, horizontal, black 'bars' across the top and
bottom of the screen. These bars increase or decrease, as the
aspect ratio changes. However, 'letter-boxed' movies,
originally filmed in extra-wide format, can be especially
troublesome when viewed on smaller TV screens, due to the
extremely reduced viewing area.
It's important to understand that the digital signal can be
transmitted in either the (4:3) or (16:9) aspect ratio.
(Although it's alleged that all DTV will be broadcast in
(16:9) at some future date)
Your DTV will be able to display both aspect ratios -
regardless of which ratio is 'native' to your set. When you
watch a program that is transmitted in (4:3) aspect ratio, on
a (16:9) screen, the image will be "window-boxed" - centered
on the screen with vertical black bars ('gray' on some models)
on both sides. When you watch a (16:9) program on a (4:3)
screen, it will appear "letter-boxed" (previously described)
with horizontal bars across the top and bottom of the
screen.
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What is
HDTV
Have you walked into your electronics store
lately and seen the big wide-screen televisions. They look
impressive and are super thin compared to your old home TV set.
These new screens are flat and can be hung on the wall (with the
proper brackets). [See example]
They are part of the new digital television era. Not all flat
displays are high definition however and more importantly, not all
are capable of showing the impressive high definition
programming.
Shopping for one of the new displays is
not as easy as it once was when you bought a new TV set. Your old
analog TV sets were basically made up of the same NTSC signal
technology, and they just were different sized screens and some had
added features. You bought a 9 inch screen TV set for your kitchen
and a 27 inch screen TV set for the living room and that was
that.
You were hooked up to cable TV or used a rooftop
antenna for VHF and UHF reception. In the old days, you tuned in
channels 2 thru 83 on the old rabbit ears antenna and the UHF circle
antenna on your TV set (manually adjusted for good reception). You
connected your VCR for recording TV shows and possibly your
2-channel home stereo gear for better sound.
Today things are going to be changing
for your home entertainment. We're moving to digital technology,
disc instead of tape, sharper visual presentation and better audio.
High Definition TV is part of this change. The transition has
already begun. For a more complete history of what has been
happening click here.
For answers to more frequently asked
questions, click here.
Did you know that High Definition
television signals are broadcast on UHF right now! That's right! A
TV station broadcasting traditional analog NTSC signals for example
on VHF channel 5 might be broadcasting HDTV signals on UHF channel
55. See this chart
for a complete listing of TV stations in the United States which
could be broadcasting HDTV programming.
Digital TV relies on a compression and
encoding scheme known as MPEG-2 to fit its stunning images into a
reasonable amount of bandwidth. In each image, the MPEG-2 software
records just enough of the picture without making it look like
something is missing. In subsequent frames, the software only
records changes to the image and leaves the rest of the image as-is
from the previous frame. MPEG-2 reduces the amount of data by about
55 to 1.
MPEG-2 already is the industry standard
for DVD videos and some of the satellite TV broadcast systems.
Compression reduces image quality from what is seen by the digital
camera at the studio. However, MPEG-2 is very good at throwing away
image detail that the human eye ignores anyway. The quality of the
image is very good, and significantly better than traditional analog
TV.
The use of MPEG-2 permits an HDTV
receiver to interact with computer multimedia applications directly.
For example, an HDTV show could be recorded on a multimedia
computer, and CD-ROM applications could be played on HDTV systems. A
digital TV decodes the MPEG-2 signal and displays it just as a
computer monitor does, giving it high resolution and
stability.
Feb. 17, 2009 marks the end of analog TV broadcasts and the beginning of digital TV broadcasts. At issue is the American households getting only over-the-air TV reception on their analog older TV sets. To continue getting TV programming after 2/19/2009, these households will have to 1) buy a new digital TV with a digital tuner or 2) obtain a converter box which will receive the digital TV signals and convert them to an analog signal. See DTV 2009 for more information on the $40 coupons you can apply for to defer the cost of the box and also how to hookup the converter box to your TV set.
How do
I get HDTV?
What
HDTV displays are available and how much do they cost?
What
do I need to see HDTV?
How
do I connect my DVD player?
Quick
HDTV Guide
What
is native resolution?
Digital TV
Manufacturers
Who makes HDTV sets?
Most of the big world-wide
electronics firms you have seen in other products such as CD
players, DVD players, audio players, digital cameras and the like
all make the high-tech HDTV displays. The following list is not all
inclusive but shows most of the brands you will see when looking for
an HDTV. The top names have warranties on their products and provide
customer support.
LG Electronics
Korean-based
LG Electronics makes TV/Video products including flat screen
HDTV.
Fujitsu
Fujitsu General America, Inc. is a leading
provider of a wide variety of innovative and highly reliable
products. Since introducing the world's first color plasma display
monitor in 1993, Fujitsu has emerged as the leader in plasma display
technology. In 2004, Fujitsu also entered the LCD Front Projector
market with the introduction of its high resolution
LCD-Projector.
Hitachi
Hitachi enjoys a unique position among
manufacturers of consumer electronics. Hitachi designs, develops and
manufactures proprietary, Large Scale Integration, or LSI
microprocessors-the intelligence behind any digital product. Hitachi
is a partner in the world's most advanced plasma display facility.
Hitachi builds a wide range of direct-view, projection and plasma
television products.
JVC
JVC Company of America is a subsidiary of
Victor Company of Japan, Limited. JVC - America is currently
marketing products in the following categories: Digital Video
Camcorders, VHS-C Camcorders, Digital Still Cameras, Super VHS
VCR’s, VHS VCR’s, DVD’s, Satellite Systems, Color Televisions
including flat-screen digital, Home Audio Components and Systems,
Personal Audio Systems, Mobile Entertainment Products and Recording
Media.
Panasonic
Panasonic makes many excellent digital TV
displays as well as a multitude of other consumer electronics
products including DVD recorders, camcorders and media.
Mitsubishi
Mitsubishi Electric digital televisions
include some of the best large-screen projection HDTV's in the
marketplace.
NEC
NEC makes Plasma digital TV
displays.
Philips
Royal Philips Electronics of the
Netherlands is one of the world's biggest electronics companies and
Europe's largest. Philips is tenth on Fortune's list of global top
electronics corporations. They are a world leader in digital
technologies for television and displays, wireless communications,
speech recognition, video compression, storage and optical
products
Pioneer
Pioneer North America, Inc. is a part of
Tokyo-based Pioneer Corporation, a world leader in digital
entertainment products. Pioneer is respected for its role in such
innovations as interactive cable TV, the Laser Disc player,
developing the first Compact Disc player for the car and the first
detachable face car stereo, DVD and DVD recording, plasma display,
and organic electroluminescent display.
RCA
RCA has been bought out and merged with several
companies in recent years but you'll still see TV displays with the
RCA logo.
Samsung
Samsung is a leading
manufacturer of home entertainment video and audio products as well
as products like phones, computers, home appliances, fiberoptics and
more.
Sanyo
Sanyo has been in the consumer
electronics business for decades and makes a variety of products
including digital TV displays.
Sharp Electronics
Sharp makes flat screen TV
displays from small 15 inch screens to very large LCD displays with
excellent picture quality.
Sony Electronics
Sony Corporation of America is the
U.S. subsidiary of Sony Corporation, headquartered in Tokyo. Sony is
a leading manufacturer of audio, video, communications, and
information technology products for the consumer and professional
markets. Sony makes both Plasma and LCD digital flat screen TV
displays.
Toshiba
A world-wide supplier of all
kinds of electronics including digital TV displays.
Viewsonic
Headquartered near Los
Angeles in Walnut, Calif., ViewSonic Corporation has quickly become
a leading global provider of visual display products selling LCD and
Plasma TV displays.
Zenith Zenith makes
both LCD and Plasma displays.
What are the popular
screen sizes in digital TV displays?
Screen sizes for the
thin TVs vary from a small 15 inch (possibly not HDTV capable) to
very large 60 inch, 82 inch and more. However most of the screens
will be in the 32 inch, 42 inch, 50 inch sizes which is what
most people want. This gives you the wide-screen view and possibly
High-Definition capability and great resolution for HDTV. A 50 inch
screen is amazingly large in a Plasma technology display. You have
to consider how much a 50 inch Plasma display weighs. It's heavy,
over 100 pounds and measuring about 60 inches wide by 33 inches high
by 5 inches deep. Bigger than 50 inch screens can be Plasma but most
likely are projection TVs (DLP, LCos).
How much do digital
TV displays cost?
Prices are coming down all the time.
Last year's $6,000 Plasma display goes for $4,500 today. Small sets
can go for $700 or less but try to get at least the 16x9 wide-screen
(most likely a 17 inch at least).
A few thousand
dollars will buy a decent digital display capable of HD while a few
thousand more will buy a much better overall display with all the
extra features. A 22 inch LCD might cost $1,600 or so and be HD
ready. The bigger displays cost the most. They don't necessarily
have a better picture.
Where should I buy my
HDTV?
There are online consumer electronics vendors such
as Vanns (www.vanns.com) located in Montana and Tweeter
(www.tweeter.com).
Also try Onecall (www.onecall.com)
located in Washington State and BHphotovideo
(www.bhphotovideo.com) located in New York
City.
Many of these vendors may not charge sales
tax to most people (those out of state) or possibly even shipping
charges. Then there are the national retail stores such as Circuit
City and Best Buy where you can take a look at the various digital
TV displays up close. Here you may find the lowest price but
the least technical expertise.
Also, if you look
around, most large cities have high-end specialty retail stores that
sell only top-of-the-line audio and video products. Some of these
types of stores have been in business for decades and have a solid
reputation although the prices will tend to be higher. You may find
the best technical expertise at these types of stores. Buy from a
trusted source known to you or someone you know and trust.
Considerations include delivery and setup, customer support and
return possibilities if all goes wrong.
What should I
look for in a digital TV?
o Tuners
Plasma
display panels (PDP) and LCD displays may contain an analog
television tuner (NTSC) and even may contain a digital television
tuner (ATSC). Check which tuners, if any, are integrated in the set.
To receive HDTV signals you may need to buy a HDTV tuner box to
decode the High-Def signals.
o Connection
jacks
You need to have plenty of audio and video
connections on the set to plug in all your components. Composite
video, component video, DVI or HDMI along with audio jacks. A Cablecard
slot might be desirable if you get your TV signals from Cable TV.
Check which connection jacks and slots are present.
o
Pixel Resolution
A 1024x1024 or 1024x768 pixel display
will not show true HDTV which is 1920x1080i or 1280x720p but it will
be close. The display's Up-conversion / down-conversion circuitry
will optimize the picture for each signal source. Here it depends
what you think is good enough but suffice it to say you need to
check the native pixel resolution.
o
Features
Some features you might want include PIP
or picture-in-a-picture where you can watch two shows at once,
a sleep timer to auto switch off the set, and digital media slots
for showing digital camera pictures etc. on the display.
o
Sound
Keep in mind that digital TV displays do
not necessarily have speakers like your analog TV has. Some do have
stereo speakers built in but if not, you'll have to connect your
stand-alone speakers up to hear the audio. For Dolby Digital 5.1
shows, you'll need the full compliment of left, right, center,
surround speakers and a subwoofer along with an amplifier or A/V
receiver to drive them.
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