      
HDTV August 20, 2007 · As TVs get more complicated, more and more people
don't know how to use them. In fact, half of people who have
high-definition televisions don't subscribe to HD cable packages — so
they aren't actually watching anything in high-def.
Then there's the federally mandated switch to digital broadcast signals,
coming up in 18 months. It's got nothing to do with HDTV, necessarily,
but it might just make your old TV obsolete.
So whether you're ready to shell out big bucks for a high-definition TV,
or you've already coughed up the cash, there's a lot to sort out if you
want to get the most out of your investment.
Happily, there are resources out there to be consulted, from technology
Web sites to programming providers to tech-savvy teens who blog happily
away about pretty much any device you can imagine.
And there's always the cable company: You may have to call them out
anyway, if you've got a new TV and an older cable box. While the cable
guy is there, see if you can get him to explain the V-chip. You'll be
glad you did: Congress wants to put them in all kinds of media players,
from iPods to game consoles.
Digital Set? Pre-Digital Picture? Try These Tips
August 19, 2007 · If you've taken
the digital-TV plunge, but you can't figure out why your 46-inch
flat-screen doesn't look as good as the store's display model did, here
are three things to check. They can help make the difference between
digital disappointment and big-screen bliss.
Know Your Signal: If you've got an HD-compatible TV, make sure you're
getting an HD signal. That means either a digital-compatible antenna to
pick up your local stations' HD broadcasts, if any, or an HD programming
package from your cable or satellite provider.
Hook It Up Right: HD signals can only be carried to your shiny new TV
from your TiVo, your cable converter or your satellite box through
HD-ready cables. Basically, you'll need one of three types: component
cables, HDMI cables, or DVI cables. Check the manual for your TV to see
which kinds it'll accept — many of the very newest TVs don't have DVI
inputs — and then shop your local electronics retailer.
Stop the Taffy-Pulling: Widescreen TVs, designed with what's called an
"aspect ratio" of 16:9, are great for watching movies and other
programming meant to be seen in a widescreen format. But many TV shows
are still filmed in the narrower 4:3 aspect ratio — the shape of most
older TVs and many computer monitors. That can mean distorted images.
You'll want to find the aspect-ratio setting on your TV (its location
will vary, but there's probably a button on your remote) and toggle back
and forth depending on what you're watching. Set it to 4:3, and the TV
won't stretch a sitcom-size signal to fill your widescreen display.
You'll get black bars to the left and right of the picture, but the
actors on that Sex and the City re-run won't look wider than you
remember. Switch it to 16:9, and those high-def Shark Week scare-fests
will show up in all their widescreen glory.
The good news: After February 2009, most programming will be created in
digital widescreen formats. For consumers who've upgraded their TVs,
these complications will fade away.
High-definition television (HDTV) is a digital television
broadcasting system with a significantly higher resolution than
traditional formats (NTSC, SECAM, PAL). While some early analog HDTV
formats were broadcast in Europe and Japan, HDTV is usually broadcast
digitally, because digital television (DTV) broadcasting requires much
less bandwidth if it uses enough video compression. HDTV technology was
first introduced in the US during the 1990s by a group of electronics
companies called the Digital HDTV Grand Alliance
High-Definition television was first developed by Nippon Hōsō Kyōkai,
and was unveiled in 1969.[3] However, the system did not become
mainstream until the late 1990s.
In the early 2000s, a number of high-definition television standards
were competing for the still-developing niche markets.
Three HDTV standards are currently defined by the International
Telecommunication Union (ITU-R BT.709). They include 1080i (1,080
actively interlaced lines), 1080p (1,080 progressively scanned lines),
and 720p (720 progressively scanned lines). All standards use a 16:9
aspect ratio, leading many consumers to the incorrect conclusion of
equating widescreen television with HDTV. All current HDTV broadcasting
standards are encompassed within the ATSC and DVB specifications.
Projection screen in a home theater, displaying a high-definition
television image.
Projection screen in a home theater, displaying a high-definition
television image.
HDTV is also capable of "theater-quality" audio because it uses the
Dolby Digital (AC-3) format to support "5.1" surround sound. It should
be noted that while HDTV is more like a theater in quality than
conventional television, 35 mm and 70 mm film projectors used in
theaters still have the highest resolution and best viewing quality on
very large screens. Many HDTV programs are produced from movies on film
as well as content shot in HD video.
The term "high-definition" can refer to the resolution specifications
themselves, or more loosely to media capable of similar sharpness, such
as photographic film and digital video. As of July 2007, HDTV saturation
in the US has reached 30 percent – in other words, three out of every
ten American households own at least one HDTV. However, only 44 percent
of those that do own an HDTV are actually receiving HDTV programming, as
many consumers are not aware that they must obtain special receivers to
receive HDTV from cable or satellite, or use ATSC tuners to receive
over-the-air broadcasts; others may not even know what HDTV is.
HDTV Sources
The rise in popularity of large screens and projectors has made the
limitations of conventional Standard Definition TV (SDTV) increasingly
evident. An HDTV compatible television set will not improve the quality
of SDTV channels. To get a better picture HDTV televisions require a
High Definition (HD) signal. Typical sources of HD signals are as
follows:
* Over the air with an antenna. Most cities in the US with major network
affiliates broadcast over the air in HD. To receive this signal an HD
tuner is required. Most newer HDTV televisions have a HD tuner built in.
For HDTV televisions without a built in HD tuner, a separate set-top HD
tuner box can be rented from a cable or satellite company or purchased.
* Cable television companies often offer HDTV broadcasts as part of
their digital broadcast service. This is usually done with a set-top box
or CableCARD issued by the cable company. Alternatively one can usually
get the network HDTV channels for free with basic cable by using a QAM
tuner built into their HDTV or set-top box. Some cable carriers also
offer HDTV on-demand playback of movies and commonly viewed shows.
* Satellite-based TV companies, such as Optimum, DirecTV, Sky Digital,
Virgin Media (in the UK and Ireland) and Dish Network, offer HDTV to
customers as an upgrade. New satellite receiver boxes and a new
satellite dish are often required to receive HD content.
* Video game systems, such as the Xbox (NTSC only), Xbox 360, and
Playstation 3, can output an HD signal.
* Two optical disc standards, Blu-ray and HD DVD, can provide enough
digital storage to store hours of HD video content.
With standard-definition TVs, the rule used to be that viewers would
feel comfortable watching a set from a distance of 3 to 6 times the
screen size in inches. With HDTV, the resolution is so much better that
you can sit closer to a larger TV without noticing the pixels. So with
HDTVs, the rule tends to be you can sit anywhere from 1.5 to 3 times the
screen size (in inches) for the best experience.
These rules have been designed to tell you where to sit in relation to
your new TV. Look at it another way: You know the size of the room you
have already, where you want to sit, and where your new HDTV should go
once you get it. So, which size TV should you get?
Doing the math backwards, you get this formula:
Minimum size= Viewing distance/3
Maximum size=Viewing distance/1.5
Doing that math straight up can give some unusual size numbers, so if we
round the math to existing common HDTV sizes we get this handy chart:
If the TV you need for your room is 40 inches or less, a flat-panel LCD
TV is your best bet. Between 42 and 60 inches, you can choose between
plasma, LCD, or rear-projection sets. Plasma HDTVs tend to be the most
popular choice in this size range, as they offer good picture quality
and flat-panel allure. Flat-panel LCDs are now competitive in price with
plasma in the 40- to 46-inch sizes, but generally not available over
52-inches--and at that size they can be pretty expensive.
Rear-projection TVs, such as DLPs or 3LCD rear-projection TVs, are often
going to be the best priced of these large-screen TVs. These sets offer
a great picture, but where flat-panel HDTVs are about 4-inches thick,
rear-projection models are anywhere from 10 inches to 16 inches--so you
aren't going to be hanging one on your wall. It turns out most
flat-panel HDTV buyers don't end up hanging theirs on the wall either.
Another rear-projection option is LCOS (liquid crystal on silicon). This
technology is highly regarded for picture quality and is generally only
available now in full 1080p resolution models. LCOS is a generic term;
the two different implementations of this technology you'll find are the
HD-ILA TVs offered by JVC and the SXRD sets offered by Sony. While there
are subtle technical differences between these two, we find both provide
excellent picture quality.
If you want to go really big with your TV , you're looking at a
rear-projection model or a front-projection model. Rear-projection
models (including LCD, DLP, and LCOS) are available up to 70 inches in
size. That's a really, really big TV set. Please measure your room
first, check the dimensions on the model you're looking at, and make
sure that's really going to fit. For screens bigger than 70 inches, you
need a front projector, also known as a home theater projector or a home
entertainment projector. These are just what they sound like; they
project the image forward like a movie projector does. The technologies
available are the same as for rear-projection TVs. If you buy a home
theater projector, you'll also need to think about the screen you're
projecting on to. Also remember that home theater projectors don't come
with built-in TV tuners, these are really just for projecting an image.
To get TV, you'll need to hook your projector up to an external tuner
and/or DVD player. At this size, seriously consider stepping up to HD
DVD or Blu-ray for your movie needs. At the very least, make sure you
have an up converting DVD player. Standard-definition images look pretty
poor at really large sizes. Also remember that if you want to go with a
front projector, you'll also need to get a screen.
When the first high-definition television (HDTV) sets hit the market
in 1998, movie buffs, sports fans and tech aficionados got pretty
excited, and for good reason. Ads for the sets hinted at a television
paradise with superior resolution and digital surround sound. With HDTV,
you could also play movies in their original widescreen format without
the letterbox "black bars" that some people find annoying.
Shopping for an HDTV?
Compare HDTV prices at Consumer Guide Products before you buy.
But for a lot of people, HDTV hasn't delivered a ready-made source for
transcendent experiences in front of the tube. Instead, people have gone
shopping for a TV and found themselves surrounded by confusing
abbreviations and too many choices. Some have even hooked up their new
HDTV sets only to discover that the picture doesn't look good.
Fortunately, a few basic facts easily dispel all of this confusion. In
this article, we'll explain the acronyms and resolution levels and give
you the facts on the United States transition to all-digital television.
We'll also tell you exactly what you need to know if you're thinking
about upgrading to HDTV.
Analog, Digital and HD
For years, watching TV has involved analog signals and cathode ray tube
(CRT) sets. The signal is made of continually varying radio waves that
the TV translates into a picture and sound. An analog signal can reach a
person's TV over the air, through a cable or via satellite. Digital
signals, like the ones from DVD players, are converted to analog when
played on traditional TVs.
This system has worked pretty well for a long time, but it has some
limitations:
* Conventional CRT sets display around 480 visible lines of pixels.
Broadcasters have been sending signals that work well with this
resolution for years, and they can't fit enough resolution to fill a
huge television into the analog signal.
* Analog pictures are interlaced -- a CRT's electron gun paints only
half the lines for each pass down the screen. On some TVs, interlacing
makes the picture flicker.
* Converting video to analog format lowers its quality.
A Toshiba analog television
Analog TVs like this one can't use a digital signal without a set-top
converter.
United States broadcasting is currently changing to digital television (DTV).
A digital signal transmits the information for video and sound as ones
and zeros instead of as a wave. For over-the-air broadcasting, DTV will
generally use the UHF portion of the radio spectrum with a 6 MHz
bandwidth, just like analog TV signals do.
DTV has several advantages:
* The picture, even when displayed on a small TV, is better quality.
* A digital signal can support a higher resolution, so the picture will
still look good when shown on a larger TV screen.
* The video can be progressive rather than interlaced -- the screen
shows the entire picture for every frame instead of every other line of
pixels.
* TV stations can broadcast several signals using the same bandwidth.
This is called multicasting.
* If broadcasters choose to, they can include interactive content or
additional information with the DTV signal.
* It can support high-definition (HDTV) broadcasts.
DTV also has one really big disadvantage: Analog TVs can't decode and
display digital signals. When analog broadcasting ends, you'll only be
able to watch TV on your trusty old set if you have cable or satellite
service transmitting analog signals or if you have a set-top digital
converter.
This brings us to the first big misconception about HDTV. Some people
believe that the United States is switching to HDTV, that all they'll
need for HDTV is a new TV and that they'll automatically have HDTV when
analog service ends. Unfortunately, none of this is true.
HDTV is just one part of the DTV transition. We'll look at HDTV in more
detail, including what makes it different from DTV, in the next section.
Important DTV Dates
* July 1, 2006: All new 25" or larger sets must have DTV tuners or be
DTV-ready
* March 1, 2007: All new 13" or larger sets must have DTV tuners or be
DTV-ready
* February 17, 2009: Proposed shutoff date for over-the-air analog
broadcasts
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