Before You Buy an LED Television

Though LED, or light-emitting diode, TVs have been widely available since 2007 confusion still looms over how this technology actually works and whether it's a better choice overall. Before you fork over the money for a shiny, new LED high definition television, it's important to know a little about it. Whether you're looking to buy an LED, LCD, plasma or other type of HDTV, it's important to compare the advantages and disadvantages of each.

LED at a Glance
The first thing you need to understand about LED TV technology is that it is actually a type of LCD TV. The primary difference between LCD and LED TVs is the screen's lighting source. While LCD TV screens are lit by cold-cathode fluorescent lights (CCFLs), LED TV screens feature an LED backlighting. So, the actual screen is based on LCD technology in both cases.

LED vs. LCD
If LED and LCD are both technically LCD televisions, you may be asking how they differ other than the aforementioned difference in backlighting. LED TVs were first designed in an effort to make screens thinner than they had ever been before. This is possible due to the fact that LED backlighting requires less space when compared to traditional CCFL LCD screens. Other than the slight variation in thickness, LEDs are generally a bit more energy efficient when compared to similarly-sized LCD TVs.

LED Backlighting
There are two main types of LED TVs -- Full-array and Edge-lit. Here's a quick breakdown of each type:

Full-Array:
As the name implies, fully-array LEDs offer a grid-like pattern of LEDs positioned behind the whole screen. These LEDs are designed to light the screen evenly. Although it's not quite as accurate compared to plasma or OLED screen technologies that feature individually-lit pixels, full-array LEDs are currently the highest-quality screen choice when shopping for an LED HDTV. The price reflects that fact as well; expect to pay much more for a full-array LED TV than an edge-lit model.

Edge-Lit:
Edge-lit LEDs are far and away the more popular of the two types of LED technologies, and for one reason '" price. The price of edge-lit LED TVs is much more affordable than Full-array screens; most LED TVs on the market are edge-lit. These screens feature LED backlighting along the four sides of the TV, which illuminate toward the center of the screen. The drawback of edge-lit LEDs is the fact that the color accuracy and contrast ratio (true blacks) is not quite up-to-par with most plasmas, LCDs and full-array LEDs. However, the technology is continually improving with better, more accurate screens being created by Samsung, Sony, LG, Vizio and other popular HDTV manufacturers.

Local Dimming
I just mentioned the fact that LED technology has been improving recently and one such improvement is called local dimming. This feature is available in both fully-array and edge-lit LED TVs, and most 2010 and later models have it. Local dimming is a "smart" feature in which your LED TV independently dims certain LEDs to help improve the contrast ratio and color accuracy. For instance, a black screen with white text or imagery on the left side would signal the TV to dim the LEDs on the right side while keeping the left side illuminated to show the text/imagery more accurately. This is really an essential feature if you value image quality.

Drawbacks
Before determining whether or not an LED HDTV is right for you, first consider the potential downfalls. I already discussed most of the advantages '" thin profile, energy efficient, local dimming improves picture quality '" but LEDs also have several drawbacks that you may find to be deal breakers.

One disadvantage of LED TV screens is the narrow viewing angle; traditional LCD televisions have the same issue. This simply means that the picture quality diminishes as you view the screen at an angle from either side. The optimal viewing angle depends upon the exact model of the TV, but in most cases, the quality progressively worsens as you view the screen at 70 degrees or more from either side of the center axis.

The other major drawbacks of LEDs were touched on earlier: picture quality and price tag. While the average consumer will be more than happy with the picture quality of an LED HDTV, a side-by-side comparison with a comparable plasma HDTV will reveal noticeably better color accuracy and contrast ratio in the plasma. However, the gap between LCD, LED and plasma HDTV picture quality is shrinking. In the end your buying decision may come down to the price, and LED TVs still have a way to go until they rival plasma and traditional LCDs in pricing.