Currently, there are two major contenders in the TV marketplace: LCD and LED. While marketed as two differing TVs to the consumer, in reality a LED TV is just another type of LCD unit. Going forward throughout this piece for clarity, they will be called LCD and LED respectively.
LCD, and subsequently LED TVs are unique machines. They are composed of two sheets of polarizing material with a liquid crystal solution between them. Within each pixel are three sub-pixels fitted with a blue, green, or a red color filter. To create a wide range of colors, varying voltages of electricity pass through each sub-pixel. These voltages adjust each sub-pixel intensity, and consequently the color intensity as well. This way, blue, green, and red light blend together in various intensities to produce a broad array of colors that then produce a picture.
Now, the major difference between a LCD and LED TV is how they are backlit. Neither an LED nor LCD TV illuminates itself, so each needs a light source to project the image. LCD TVs use cold cathode fluorescent lamps (CCFLs) and LED TVs use, unsurprisingly, light emitting diodes (LEDs).
When shopping for TVs, you will see differences in resolution and refresh rate between the product. While 4K TVs are new to the market, offering a resolution of 3840 x 2160, they are considerably more expensive than their 1080 brethren are. As a long-term investment though, it could prove to be a better buy as content begins to be created in 4K resolution.
Refresh rates, commonly marketed at 60Hz, 120Hz, and 240Hz, are only as good as the source footage. Today’s HD content, like a Blu-ray DVD, is shot at 1080 resolution at 60 frames per second. What TVs with a 120Hz or 240Hz do is creating additional frames based on the source image through some mathematical wizardry. This may help with some image stabilization issues; it can create images that look artificial though. In the end, refresh rates should not be a deal breaker when looking at TVs.
Known in the TV community as the TVs for a tight budget, LCD TVs are simply lower end models now. LED TVs and their quickly falling prices are pushing them out of the marketplace.
The CCFLs that backlight LCD TVs are similar to the fluorescent lights used in overhead light fixtures and lamps; instead of being a cylindrical bulb we are accustomed to, it is one large flat panel situated behind the display. CCFLs emit light when electricity excites the mixture of gases inside the bulb. These gasses create ultraviolet light that is absorbed by the bulb’s fluorescent coating. Visible light is produced when the UV light hits the coating.
While an LCD is cheaper, they do have their downsides. Using CCFLs as backlighting, LCD TVs have a thicker frame than their LED counterparts that make them more difficult to mount.
The room the TV will be place in is important. LCD TVs do not produce bright vivid colors, or deep vibrant blacks. This is due to their use of CCFLs. If the TV is going to be in a particularly dark or bright room, an LCD TV at times will appear washed out or lacking in color depth. The image will lack vibrancy.
LCD TVs are still great TVs. They are just not for the videophile that craves the best of the best in image quality or versatility. If you are looking for an additional TV for a child’s playroom or other non-essential movie viewing room, the price of an LCD is hard to pass up.
Being the newest competitors to the market, LED TVs are quickly falling in price. Their thinner design, thanks in part to their usage of LEDs to backlight the display as opposed to the bulkier CCFLs, creates not only a product that is of a better quality, but can be a visually stunning centerpieces for a room.
What makes LED TVs much more versatile than LCD TVs is a technique called local dimming. The idea behind local dimming is that it allows for greater control over LEDs, allowing for control over each individual LED. Depending on the picture, the LEDs can be dimmed or turned off entirely. This allows for greater contrasts between lightness and darkness, and can help achieve a greater picture quality that eludes LCD TVs.
While not all LED TVs come equipped with this feature—it depends on the type of LED TV, which will be explained shortly—this allows for greater control over the LED backlighting.
There are actually three types of LED TVs for sale: edge-lit, direct-lit and full-array. Each type offers benefits to the TV game.
Full-array LED TVs can produce the best images with the best contrast. Full-array LEDs, distributed evenly behind the LCD, allows for far greater and more efficient local dimming.
Edge-lit LED TVs are typically the thinnest TVs available, but like most things in technology, full-array TVs are slimming down quickly, almost eliminating any thickness differences between the two. In an edge-lit TV, the LEDs are along the edges of the screen. They are located at the bottom, the sides, or all around. Edge-lit TVs don’t have the ability to produce local dimming. Without local dimming, image contrast is not as great as it would be with a full-array LED TV.
The third type of LED TV, called direct-lit, is similar to a full-array TV. While the LEDs are directly behind the screen, significantly fewer diodes cannot produce local dimming. Direct-lit TVs are also thicker than their counterparts are. There is a need for more space behind the screen to help reflect the LED light over a larger area behind the screen. Budget LED TVs typically come with direct-lit displays.
Like LCD TVs, LEDs also have their pros and cons. While they produce significantly better images with wonderful contrasts, they do command a higher price. Placement should also be a factor in which TV to go with as well. A full-array LED TV is perfect for a media room designed with deep soft-leather armchairs and mood lighting, but would be overkill for most other instances.
Buying a TV is a large purchase for many. No one wants to buy technology that will be quickly antiquated, which is hard to do with the pace of technology moving so quickly, but no one wants to spend a fortune either. While LCD TVs may seem like the dinosaurs in the room, they still do have many functions that will fit most needs, especially at their lower price point. No child needs a full-array 4K LED TV to wath Mickey Mouse Clubhouse.
Full-array LED TVs are best for people demanding the absolute best in image quality, but like everything else, placement is key. In a normal living room with lights and windows, the quality difference could be indistinguishable for many when compared to a LCD TV.
Regardless of whatever your purchase, remember to always shop around, read the reviews, and buy what you think is best for your needs.