What's the difference between plasma and LCD?
Plasma TVs are great at delivering high-definition TV in a stylish case
that's thin enough to hang on a wall. LCD TVs can do the same, but there
are some fairly important differences between the two:
- Plasma TVs are available
in fewer screen sizes than LCD TVs. Though more screen sizes are available
than before, the smallest current plasma TVs are 42 inches, while the
biggest ones sold to consumers are 65 inches. LCD TVs, on the other hand,
can range from just a few inches to 75 inches in size. For home theaters,
LCD TVs with screen sizes from 32 inches to 65 inches are most popular.
- Plasma TVs
work better in dimly lit rooms. Though plasma TVs often do a better
job of creating deep blacks and displaying details in shadowy areas of
the picture, most can look washed out in rooms that are brightly lit. That's
less of an issue for LCD TVs, which produce more brightness. Additionally,
many LCD TVs have an adjustable backlight so brightness can be dialed up
or down to accommodate a variety of room-lighting conditions. Many LCD
TVs now use LED backlighting instead of the formerly popular cold-cathode
fluorescent lamp (CCFL) backlights. These LCD TVs -- often called LED TVs
-- do a much better job of producing blacks, and some are even competitive
with the best plasma TVs in that regard.
- Plasma TV screens are more prone to glare. That's
because many use a screen that's more likely to reflect any light sources
that are in the room. On the other hand, some do a better job with
ambient light, while some LCD TVs now use a more reflective screen.
- Plasma screens
have good viewing angles. With an LCD TV, you often need to sit more
or less directly in front of the screen to see the best picture. That's
not an issue with a plasma TV. Even those sitting a bit off to the side
will enjoy the full picture quality that the set is able to deliver.
- Plasma TVs
are more energy-efficient than they used to be, but they still
trail LCD TVs by a wide margin. Despite improvements in the latest generation
of plasma sets, LCD televisions are typically far more efficient to operate.
Important features
Choices among plasma HDTVs have been reduced of late, but there are still
plenty of options to consider and lots of decisions to make. Here are just
a few things to point you in the right direction:
- The more HDMI inputs the
better. All HDTVs are equipped with at least one HDMI input, and better
models have multiple HDMI inputs. Most modern home theater equipment
-- including HD-capable cable and satellite TV boxes, upscaling DVD players,
Blu-ray Disc players and many home-theater audio receivers -- uses this
connection, which makes it possible to route video and audio on a single
cable, minimizing signal loss and cutting down on cable clutter. In addition,
this input, which supports HDCP (a system intended to prevent people from
making copies of high-definition movies), is required for watching Blu-ray
movies or upconverted standard-definition DVDs at full 1080p resolution.
Most current HDTVs support the latest HDMI specifications, which allow
for the passage of 3D video and to send audio back to a home theater receiver
(audio return channel) that's also equipped with the latest HDMI ports.
- Match TV size to the size
of your room. Because HDTVs have much higher resolution than conventional
TVs, you can sit closer than you formerly could. That means you can
get away with a bigger screen in a smaller room.
- Decide on the resolution. While
most HDTVs now have 1080p resolution, many experts say that at screen
sizes of 50 inches and below, most people can't see the extra detail at
typical seating distances. If you sit 10 feet or more away from the screen,
and/or your screen is 50 inches or less, a 720p HDTV can be a sensible
and economical choice.
- Verify that the plasma TV comes with a stand or
mounting hardware. Most plasma TVs come with a basic table stand. Wall-mounting hardware
must be bought separately and the most versatile and sturdy mounts -- a
good idea with a heavy plasma TV -- can get expensive (about $200 or even
more).
- Shop
around for prices. In our research, we often found large price differences
from retailer to retailer, so it pays to look around. Note that the
lowest prices sometimes come from unauthorized dealers, which, depending
on the manufacturer, can cause warranty problems if something goes wrong;
see below.
- Check the manufacturer's policy before buying online. Some manufacturers
have strict policies regarding authorized dealers. In those cases,
if you buy your plasma TV from an unauthorized dealer you'll probably violate
the terms of the manufacturer warranty, though the retailer might
offer a substitute warranty. While there can be a substantial difference
in price between authorized and unauthorized dealers, if you plan on buying
from the latter, be sure to calculate your threshold for risk on such
a large purchase, and ask the dealer about warranty coverage.
Burn-in no longer an issue for plasma
Burn-in, caused by damaged pixels that leave a permanent ghost of a static
image on the screen, was a problem with early plasma models. However, new
technology reduces the risk of burn-in, and experts generally say it's no
longer a concern with most plasma TVs. LCD TVs have no burn-in risk.
Temporary image retention is a similar problem but is less severe. In this
case, a static scene leaves behind an annoying ghost that takes several minutes
-- or more -- to completely disappear. Some plasma TVs include anti-image-retention
features such as an eraser function that removes image retention quicker
or a pixel shifter or pixel orbiter, which imperceptibly moves an image around
the screen by a pixel or two. Image retention can be a problem with all plasmas,
but recent reviews indicate that LG plasma TVs are a little more susceptible
than plasma TVs from other makers. Reports say that temporary image retention
seems to decrease as a plasma display ages.