Hardware Reference
In-Depth Information
ms or less adequate. If you watch a lot of HD video, look for a model rated
at 5 ms or less. If you're heavily into extreme gaming, look for a model
rated at 3 ms or less.
Backlighting
LCD displays backlight the image one of two ways:
CCRT
Most displays use
cold cathode ray tube
(CCRT) illumination. CCRTs are
similar to fluorescent tubes and are subject to failure and to gradual
dimming over time.
LED
Some premium displays substitute white LEDs for the CCRTs. Entry-
level LED models—which are still more expensive than CCRT models—
are
edge-lit
, with LEDs along the edges of the panel. More expensive
full-field
LED displays use a large numbers of LEDs behind the entire
surface of the panel.
LED backlighting has several advantages. First, LEDs do not burn out
or dim noticeably over time (a typical LED might dim to 50% of its
original brightness after 50 years of constant use). Second, LEDs can
be significantly brighter than CCRTs, which allows higher contrast and
a brighter image. Third, full-field LED displays can greatly increase the
dynamic contrast range of the image by selectively illuminating only
some of the LEDs in the array. In brighter image areas, all LEDs are lit;
in dimmer areas, only a fraction of the LEDs are lit.
We consider CCRT displays acceptable for almost any purpose. Rather
than spending money on LED backlighting, we'd spend it on a larger or
higher-resolution CCRT display—for now, at least. Currently, about 10%
of all LCD displays use LED backlighting. As the technology becomes less
expensive, we expect it to replace CCRTs entirely.
Minor features
We suggest you choose your display based on the factors we've already
discussed. If those aren't sufficient to narrow down your choice to one dis-
play, it's time to start looking at less important factors. Taken individually,
all of these “extra” features may be minor, but taken as a group they may
be enough to swing your decision to one particular model.
Some displays include built-in speakers, which are at best mediocre but
may be good enough for your purposes (if only to reduce desktop clutter).
Some displays also include a built-in microphone that's useful for Skype
and similar VoIP services. Although it is less common than it was a few
years ago, a few displays include a built-in webcam, which is useful for
Skype or recording YouTube videos. Finally, to reduce desktop clutter, a
few displays include a built-in USB 2.0 hub. Note that some of these are
passive hubs, and may not have sufficient power for many USB devices.
Others are powered USB hubs and work just the same as any other USB
hub.
