If it's been a while since you bought your last TV, you've probably noticed the technological landscape has changed considerably. Gone are the bulky, heavy CRT and projection screen televisions; plasma and LCD televisions now dominate the market, and new ultra-flat LED TVs are the latest hot sellers. But what's the difference? We'll give you the skinny on the ins and outs of flat panel TVs and the new age of home theatre.
|Panasonic 50" C-Series Plasma TV||Sony Bravia 52" V-Series LCD TV||Samsung 55" 120Hz LED TV|
|How It Works
A Plasma TV panel is made up of thousands of tiny cells. Each of these cells contain a combination of xenon and neon gasses that glow when electrified. Each cell has three parts coated with different phosphors: one for red, one for blue, and one for green. The ultraviolet rays given off by the plasma causes the phosphors to glow. By varying the current, the intensity of red, blue and green sub-pixels are mixed to create one colour.
|How It Works
Each pixel of an LCD TV consists of a thin layer of liquid crystal molecules between two pieces of polarized glass. When a varying electrical current is applied, the liquid crystal molecules twist and untwist, either blocking the florescent backlight or allowing it to pass through to the screen. Each pixel of an LCD panel is divided into three sub-pixels, one each for the colours red, green, and blue, the light from which mixes together to create a single, unified colour.
|How It Works
LED TVs consist of a screen of tiny one-way electronic semi-conductors called diodes which emit a large number of photons at the atomic level, and these small particle-like packets of energy and momentum are what make up the basic unit of light. Each pixel in a LED TV is made up of individual LEDs coloured green, red, and blue, colours which can be mixed together in varying intensities to create any of a million possible colours.
Plasma screens reproduce blacks and contrast better and usually have better viewing angles (up to 180 degrees). Plasma TVs are usually the top pick for sports fans and action movie buffs since they respond quickly and suffer very little motion blur.
LCDs are better for brightly lit rooms, and for playing video games because they don't burn-in static images. They're lighter, so they mount or move easily and tend to use less power than plasma TVs. LCD TVs used to get a bad rap for blurring fast action in sports and movies, but newer models have almost eliminated plasma's edge on that score.
LED TVs feature very high contrast ratio, almost zero motion blur, and true blacks. They retain their colour even in bright sunlight and reduce glare. The technology behind them means LED TVs are ultra-slim and currently the thinnest TVs on the market. They're also the most eco-friendly, using on average 40% less power than LCD televisions.
The rule of thumb for wide-screen TVs is to sit no further away than three times your screen’s diagonal measurement, and no closer than 1.5 times that measurement. Any further and you miss the high-definition details you’ve paid for; any less and you’ll be more aware of the individual pixels than the overall picture.
However, the distance also depends on what you’re viewing. If you’re still watching many programs produced in lower-quality analog format, you’ll want to sit further away, so that you don’t notice the fl aws as acutely.
Other important factors to keep in mind when choosing the size of your screen include the viewing angle and how many people will be watching in the room. LCD screens have a narrower angle of viewing than plasma screens. For LCDs it’s 90 to 130 degrees, compared to plasma screens’ 180.
So, an overlarge screen won’t necessarily accommodate more viewers if the type of screen doesn’t allow viewers sitting off to the side to enjoy a high-quality picture.
In fact, the best way to view a TV is head-on, with your eyes level with the middle of the screen.
|Screen Size||Range (Feet)|
|26||3.3 to 6.5|
|30||3.8 to 7.6|
|34||4.3 to 8.5|
|42||5.3 to 10.5|
|47||5.9 to 11.8|
|50||6.3 to 12.5|
|60||7.5 to 15.0|
|65||8.1 to 16.2|
HDTV or High Definition Television is a way of broadcasting television signals digitally, providing significantly higher resolution than traditional analogue forms of broadcasting.
Analogue format uses radio waves that suffer the farther away from the source they get. Artifacts and distortion can occur as the signal gets weaker. Digital signals, however, are transmitted using binary, which is a series of zeros and ones. Even with a weak signal, as long as the television can still tell the difference between the zero and the one, the picture will be strong and clear, without distortion.
HDTV cable boxes and satellite receivers offer up to ten times the resolution of standard analogue TV signals, transferring far superior picture quality, greater clarity, smoother motion, richer colours, and surround sound.
To be considered High Definition a signal must carry a resolution of 720p (progressive), 1080i (interlaced) or 1080p (progressive).
Interlaced frames are displayed in two fields or passes. Each field contains every other line of the picture, and an interlaced TV displays the first field of alternating lines over the entire screen, and then fills in the gaps between the lines with the second pass.
Progressive Scan televisions display every line of the picture in every pass, from top to bottom. Because there are never any gaps in the picture, progressive scan results in a more detailed, less flickered image that is ideal for fast moving action and sports.
HDMI stand for High Definition Multimedia Interface.
HDMI is emerging as the new connection standard for HDTV and consumer electronics, adopted by over 300 companies worldwide, including leading television manufacturers, computer companies and the gaming industry. HDMI is a type of digital connection that's capable of transmitting high-definition video of up to 1080p resolution at 60 frames per second and the best of high-resolution audio such as Dolby TrueHD and DTS-HD Master Audio.
HDMI is the first digital cable to combine uncompressed High Definition signals and 8 channel audio in a single cable, which can significantly or altogether remove the “cable clutter” behind your entertainment system.