High Def Talk Part I:
HD Displays
Background
Let's take a break from
cameras, computers, and printing for a bit and take a look at high
definition television and home theater. After all, those of us who
are interested in the best photographs, camera equipment, computer
equipment, and printers are often interested in getting the best picture
when it comes to home entertainment as well. I find it interesting
when I meet photographers who have some of the most expensive
photographic equipment, claim to be home theater or AV (audio-video)
fans, yet are still watching a 54 inch big screen TV from the late 80's
or early 90's. I've even heard the phrase: "My DVD's look great.
How much better can it be?" I'll try to answer that question in
this article that is geared toward those of you who have not yet made
the leap to HDTV and might be wondering if it is time. If you are
an "HD nut" who frequents
avsforum,
you'll likely get very little out of this article as you are already
ahead of the curve.
SD versus HD
What is "high definition" and how
does it compare to "standard definition"? Broadcast TV, based on a
display format that was conceived in the 1930's in black-and-white and
later modified to carry color video in the 1950's, offers a resolution
of about 330 x 245 pixels. SD or "standard definition" is a
relatively new term that refers to a digital video format
of approximately 640 x 480 pixels interlaced (480i). While this is
better than the old broadcast standard (and is the reason why standard
DVD's look better than TV), 640 x 480 is not nearly enough resolving
power for the larger (36 inch+) sets used in home theaters. Just
walk up to anyone who is digital photography savvy and tell them that
you are thinking about printing a 36 x 24 inch print from a 640 x 480
shot taken with a cell phone. When they're finished laughing and
finally get up off the floor, realize that you're doing almost the same
thing by watching that 640 x 480 DVD on your old 54 inch TV!
If you live in an area where you are
able to get local TV stations on a television with a "rabbit ear"
antenna, chances are you already have high definition signals coming
through the airwaves to your home. You simply cannot watch them
because you don't have a high definition set. High definition
comes in two basic formats: 720p and 1080i. 720p is 1280 x 720
resolution and pixels are displayed progressively so that all 920,000
pixels are displayed in each frame. 1080i is 1920 x 1080
resolution but it is interlaced, meaning that only the odd or even lines
are displayed with each frame. A newer format, 1080p, is now being
supported in many displays but as of this writing, there is very little
content that is actually available in the 1080p format so most of the
1080p sets just take a 1080i signal and deinterlace it. Still,
1920 x 1080 is 2 million pixels of resolution. Compare that to the
640 x 480 (300,000 pixels) available on a standard DVD. The best
high definition material is over 6 times the resolution of a standard
DVD.
In the eye of the
beholder
It's difficult to describe how much
better HD is when compared to SD. You simply have to see it for
yourself. Many compare HD to the feeling of looking through a
window at the actual scene. The clarity, texture, and dynamic
range are amazing. So much so that once you get used to HD, it is
difficult to watch SD! I'm so used to HD now that whenever a
football game is broadcast in SD, I literally cringe. SD looks so
out of focus and so devoid of detail that it almost gives me a headache
when I watch something with a lot of action like a sporting event in SD.
Of course, these don't look nearly as good as a DVD due to compression
artifacts and the re-processing involved with broadcast SD signals on
satellite or digital cable. Upsampled DVD on an HD monitor can
actually look nearly as good as high definition even though, technically
it is not high definition: most likely 480p (640 x 480 or 720 x
480 progressive). When asked to describe HD versus SD, you'll
likely get a different answer from everyone you ask but there's nothing
like the first time you see true HD material on a true HD set.
It's something you'll never forget!
"Fake" HD
As we know, "high definition" refers
to a video format that consists of either 1280 x 720 pixels or 1920 x
1080 pixels. If you walk into a store and they are piping video
from a standard DVD player through their sets, you'll know immediately
that you are not looking at anything high definition because DVD's are
480p (640 x 480 resolution) and are therefore not considered high
definition. Technically, 480p is considered EDTV (enhanced
definition TV). EDTV is actually a major advance over SDTV, but it
still falls short of high definition. Be aware of sets that are
marked EDTV. If it is marked EDTV, it is not a high definition
set. Some smaller plasma TV's are EDTV as are some sets marked
"high definition compatible". High definition compatible is often
used to indicate that the set can decode an HDTV signal, not that the
set itself is HD! Suffice it to say that if you are in the market
for an HDTV, make sure the store where you are evaluating the sets is
piping a true HD signal to the sets and that the set itself is truly HD.
Display types
Different types of displays (LCD's,
plasmas, DLP's) have their advantages and disadvantages. Any true
HD set you buy today will certainly look many times better than a
standard TV, but what type of set is right for you? Let's take a
quick look at a few of the most popular display types and look at their
advantages and disadvantages.
Plasma: Plasma televisions are
actually not that dissimilar from older tube sets. They use
phosphor just like the old tube sets. The difference is in how the
phosphor is excited (lit). In a CRT (tube television), a beam of
electrons scans the phosphor, lighting "pixels" in sequence. In a
plasma TV, the phosphor is lit with individual electrodes under each
pixel. The obvious advantage is size. Since plasma TV's
don't need any projection, they are made as flat panels that are very
thin and can be hung on walls or used in cramped spaces. Plasma
TV's are some of the most vibrant sets with excellent dynamic range
(rich blacks and bright whites) and are currently the best technology on
the market for viewing at an angle, as plasma televisions don't fade
when viewed off-center. Almost all consumer plasma sets as of this
writing use the 720p HD format. That is, they have a resolution of
about 1280 x 720 pixels for plasma sets 46 inches and larger. Due
to limitations in the plasma technology, 1080p (1920 x 1080 resolution)
plasma sets are just now being introduced to the marker in sizes under
60 inches, so if you are looking for a plasma set that is 60 inches or
smaller, you'll be getting a 720p set unless you want to pay $10,000 or
more. Burn-in, where static images can be "burnt" into the screen
permanently, is not much of an issue on the latest plasmas but you
should avoid static images as much as possible during the first ~100
hours of operation. In addition, if you plan to do a lot of video
gaming, an LCD may be a better choice because static images like radars,
scores, and health meters can eventually be burned in if left on a
plasma screen for extended periods of time.
LCD: For years, LCD (liquid
crystal display) televisions have struggled to compare to plasma TV's.
The most recent LCD models have all but caught plasma TV's on every
front except off-angle viewing. Today's LCD's offer less fade when
viewing from an angle, are brighter, have better blacks (better dynamic
range) and have better response times, meaning that they don't "blur"
fast moving objects like older LCD sets. In addition, it's easier
to manufacture smaller LCD screens (under 60 inches) with a higher pixel
count compared to plasma TV's, so there are a fair number of 1080p (1920
x 1080 resolution) LCD sets available at the 55 inch and smaller sizes,
making them boast higher resolution than plasma sets. There is
still some color and contrast fade when moving to off-angle viewing, but
the very latest models show a lot of promise here, with very little
noticeable fade when viewing from an angle. Things tend to change
quickly as far as display technology, but as of this writing, some of
the latest 1080p 50 to 55 inch LCD sets top the list as the highest
quality HD sets available with the least number of drawbacks (such as
uneven lighting, ghosting, "hot spots", seen with many projection type
TV's)! Like plasma displays, LCD's are flat panels that can be
hung on a wall and they are often even lighter/thinner than plasmas.
Screen burn-in is not an issue with LCD displays, making them the
display of choice for gamers.
DLP: DLP (digital light
processor) televisions have been around for about a decade. They
are a form of rear projection television that uses tiny mirrors to throw
light on the front screen. These sets are not flat panels and are
therefore a bit bulkier than plasma or LCD TV's, but they can be very
cost effective. They tend to be cheaper than plasma or LCD sets of
comparable size and they do offer an excellent picture. I'm not a
big fan of projection televisions as they tend to produce a less evenly
lit picture and my eyes are quite sensitive to blooming, color
inconsistencies, fade, and the "rainbow effect" that you can sometimes
see on DLP sets. Any projection set will tend to be a bit less
sharp than a flat panel set due to the fact that light is being "thrown"
at a distance rather than being created at specific points on a static
(non moving) panel. As with LCD panels, screen burn-in is
generally not an issue with DLP displays.
SXRD: SXRD, short for Silicon
X-tal Reflective Display, is a Sony acronym for a technology known as
LCOS (liquid crystal on silicon). It is similar to DLP in that it
uses a reflective surface but instead of using mechanical mirrors,
liquid crystals are used to reflect the light from the projector onto
the front screen. Again, this is a projection TV so it is not a
flat panel and will take up more space than a plasma or LCD TV.
Sony SXRD sets typically have a better picture than DLP sets and some
people believe they have a "film" or "movie theater" look unrivaled by
any other display type. As I mentioned under DLP, I'm not a fan of
projection TV's just because I'm sensitive to the contrast and color
fade that occurs when viewing projection TV's at an angle. I also
miss the silky smooth uniformity of plasma and LCD sets when I have to
move (walk) in front of a projection set as I can always detect the
bright spot from the projection lamp(s) moving across the screen with me.
Others may prefer SXRD technology over plasma and LCD due to the
film-like look appearing less like "pixels". Here again, beauty is
in the eye of the beholder. Since SXRD displays are basically LCD
on silicon, they generally do not suffer from burn-in.
Bottom line: The bottom line
on choosing a display is to first determine whether or not the display
is truly high definition. To be high definition, the display must
have 1280 x 720 pixels or more and should have an "HD" logo. Stick
to models marked HDTV and shy away from models marked EDTV. When
you have limited your search to HD displays, let your eyes be the judge.
Different people look for different things in a display. Some pay
more attention to contrast and saturation while others are more critical
of resolution, pixels, and sharpness. The real bottom line is that
you should pick the set that looks best to you! Keep in mind that
different display types work better in different environments with
plasma and LCD displays generally being better in rooms with bright
lighting (sunlight entering a window for example). Once you've
picked your favorite set in your price range, it wouldn't hurt to leave
the store and do a little research. Try Googling the model number
or even the model number and the word "problem" to see if other users
are experiencing any common issues with that set. Sometimes you'll
find complaints of color blooming, ghosting, banding, or other issues
and that may give you some things to double check before you buy.
Any common problems are usually described or displayed with enough
detail that you'll be able to look for the problem in the set you picked
to see if it is an issue for you.
HD Content
Before buying an HD display for your
home theater, it would be wise to be aware of the HD content that is
actually available to you. Broadcast HD is accessible in most
locations in the form of digital cable, satellite, or fiber services.
If you have cable TV, chances are your cable provider offers "digital
cable" that includes at least a few HD channels. Note that the
fact that a channel is "digital" does not necessarily mean that it is HD
(it could be SD just broadcast in digital format), so be sure to ask
your cable provider how many/what channels are offered in true HD and/or
check out their web site. If you are interested in cable HD, some
displays offer a cable card feature, so you might want to check
compatibility of the TV with your cable service, although that is not a
necessity since your cable provider can provide you with an (external)
cable box.
Verizon FIOS is a promising fiber TV
and internet service that has a lot of promise, but it isn't likely to
be available in your area as coverage right now is extremely limited.
To find out if FIOS is available in your area,
check here.
If you live in the boonies and don't
have cable or FIOS service and/or you don't like the selections offered
by those services, there's always satellite TV. Right now,
Dish Network has the greatest
selection and number of true HD channels available in any service
offering high definition content since Dish has taken over the Voom HD
satellite service. DirecTV
also offers HD channels and while they plan to offer many new HD
channels in the next year, their selection of true HD channels is more
limited as of this writing. If you already have one of these
services but you don't get high definition channels right now, you may
need new equipment and you may be required to pay an install fee and a
small monthly fee to access the HD channels. Check the web sites
of the service in question for more info. All services that offer
HD content also offer DVR's that can record HD content as well.
When choosing a satellite provider, find out whether or not they offer
your local (ABC, CBS, NBC, Fox) channels in high definition via
satellite. If not, you may be required to get these OTA (over the
air) with an antenna connected to the satellite receiver.
If you live within say 30 miles of a
city that has local TV channels, chances are you can get some HD content
for free (or at least with no monthly charges). If your display
didn't come with a built in tuner that can handle "over the
air" TV broadcasts, you'll need to buy a tuner that is capable of
receiving high definition broadcasts. What you're looking for is a
tuner that is labeled as an ATSC tuner. In most cases, a good indoor antenna is sufficient to
receive these channels but if you need an antenna, check to see whether
you need a VHF or UHF antenna as HD can be used on both frequency
ranges. To see how far you are from various TV stations and what
type of antenna you need, try visiting
antennaweb. You can simply
enter your ZIP code and click "Submit" to see the TV stations near you
and the antenna type/size needed. Note that channels with a
sub-channel (2.1, 11.1, etc.) are "DT" or digital television.
Those are the channels that are broadcast in digital format and are
likely to offer high definition content although the DT designation does
not guarantee that the channel broadcasts HD.
After broadcast HD comes HD content
on other media such as HD-DVD and Blu-Ray. Movies are starting to
be released in the HD-DVD and Blu-Ray formats now and most online rental
services offer the formats at no additional charge over standard DVD's,
but selections are limited and the two formats are still competing with
no clear winner in the format war. In addition, current HD-DVD and
Blu-Ray players can be expensive (about $500 for HD-DVD players and
$1000 for Blu-Ray players) and are relatively slow to start up.
There's also talk of players in the future that may be able to play both
formats, but no "hybrid" players exist as of this writing. Simply
put, it may be best to wait a year to see where these technologies are
going unless you have deep pockets and just want some HD to show off
because you are limited as far as HD content. A good upsampling
(standard) DVD player may be a more cost effective investment until the
HD media markets settle a bit.
Summary
While this article focused on high
definition displays to be used in home theater applications, there is
certainly a lot left untouched. If you are left wondering about
which connections to use, HDMI versus component, audio options, HD-DVD
versus Blu-Ray, backlighting, or other aspects of home theater, those
aspects will have to be covered in a future article. And again,
this article is aimed at those of you who have been wondering if it
might be time to make the leap to HD and some things to look for at the
starting line. Just be warned that if you are easily obsessed,
home theater and "high definition" can be quite expensive. While
my own setup is quite modest, I've seen people spend $85,000 or more on
true home theaters! On the other end of the
spectrum, it is possible to set up a good HD theater for $3,000 with
$1,500 being about the bottom entry point, so there's something for
everyone. To start, try to pick a store that has a home theater
section with a large selection of displays and knowledgeable/helpful
staff. Let them help you but don't let them push this week's sale
on you. Take your time, use the information from this article, and
make the decision that is best for you and I believe you'll find that HD
will quickly become a necessity in your home theater. If you're
reading this article soon after release, you may still have time to get
that HD set for the big game! :-)
Mike Chaney
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