Television Buying Guide

Benefits of TV (back to top)

The day-to-day grind of most people's lives is pretty stressful I think you'd agree. People tend to look for a quick escape from reality to break free from those high stress situations. Most people look forward to unwinding at home after a hectic work day...enter the Television. A boon to mankind, the invention of television has helped in more ways than imaginable and is truly a phenomenon that changed the landscape of human society almost overnight. A television can be used for anything from enjoying an afternoon siesta to watching re-runs of popular soap operas, to travel shows, game shows or even live broadcasts such as beauty pageants, sports events, news, and on and on.

Recent developments in computing technology have introduced various forms of entertainment for the masses. One such example is gaming consoles. Gaming consoles require an external display unit for rendering the images for playability. The usual display device is the television screen. High resolution or high definition televisions (HDTV) make it possible for gaming consoles to display beautiful true-to-life imagery and animation graphics. Such a potent combination is a hit amongst kids and adults alike.

Another purpose the television can serve is as a replacement for the typical movie theatre. The demand for home theater systems has led to the invention of alternate television display technologies that allow larger screen sizes. Technologies such as LCD TV or the Plasma TV can be built to sizes of up to 80 inches without any compromise on details or even color reproduction.

Television sets are available in various screen sizes and manufactured with various different technologies. The main difference lies between an analog television set and a digital television set. An analog TV is based on the older Cathode Ray Tube (CRT) technology for displaying moving images. The newer range of television sets are manufactured using either of the LCD, TFT-LCD, Micro-display or Rear-Projection, or the Plasma display technology, each of these technologies differ from each other in the way the image is finally reproduced. These technologies also differ from the conventional CRT display screen by way of size, clarity, weight, thickness and overall rendering of color and object details. Sound re-production though can be enhanced using an external sound processing unit such as what you might find in a stand-alone home theatre system.

High resolution TV sets should also incorporate high definition TV or HDTV compatibility due to the high-quality signal broadcasts fast catching up with prime channel broadcasting companies. Compliance should also be offered in terms of connectivity to regular PCs for the reason that most TV sets now have the ability to double as a PC monitor or even as gaming console screens. With advanced gaming consoles on the horizon, high resolution TV sets are much in need.

1. How TVs Function (back to top)

A television is simple device that converts radio waves broadcast into the atmosphere into audio and video outputs. The radio waves, or program transmissions as they commonly known, are specialized transmission signals carrying the actual audio and video content.

A television unit basically interprets these signals through the use of an external aerial antenna or a satellite dish antenna attached to it. The internal electronic circuitry decodes the signals absorbed by the antenna and produces the original audio/visual content on to the screen. Due to the separate electronic mechanisms involved in decoding the audio and the video content, the entire unit housing the components is called a television 'set'.

Television sets come in different shapes and sizes. Each differs from each other across a host of features and functionalities. Apart from screen sizes, television sets are manufactured based on various technologies. The following is a list of technologies available in the market that caters to different people with a different set of needs:

• Cathode Ray Tube (CRT)
• Liquid Crystal Display (LCD)
• Thin Film Transistor Liquid Crystal Display (TFT-LCD)
• Micro Display
• Plasma Display

• Cathode Ray Tube (CRT) (back to top)

The simple analog television set was developed in the early 1930s. This technology was developed using a simple mechanism for producing images. A glass tube is coated with colored filaments on the inner side which is bombarded with charged electron particles. This bombarding illuminates the other side of the glass tube according to the respective colors and as a whole reproduces the entire image. This technology is called the Cathode Ray Tube (CRT) technology. While being the least expensive to manufacture, it is a refined technology that can still provide the best overall picture quality.

 

• LCD TV (back to top)

A Liquid Crystal Display (LCD) screen is based on the illumination of millions of tiny crystals, called pixels (picture elements), excited by an electric current. It is usually referred to as a Passive Matrix LCD screen. Each pixel emits different intensities of light and color according to the actual image. Most LCD TVs differ from each other with respect to the number of colors displayed, the contrast ratio and refresh rate of the screen. A high value for color and contrast ratio would produce picture rich in overall details and quality. LCD TVs consume only one-third the power consumed by CRT televisions of the same dimensions. LCD TVs are as thin as 4 inches and generally weigh a maximum of 10 pounds, allowing for saving up to 90% of space. It belongs to the category of digital displays as it can also display computer graphics as well as high-definition and standard TV broadcasts. It can also generate better quality graphics when fed a pure digital signal (DVI, HDMI, or FireWire) rather than an analog connection.

 

• TFT-LCD (back to top)

An evolved version of the LCD screen technology, a Thin Film Transistor LCD (TFT-LCD) television is based on the same principle as an LCD TV. The major difference between the two, is the underlying technology that allows the TFT-LCD screen to draw images with greater clarity, color richness and details at higher contrast ratios, all these at a faster speed compared to the older LCD screen. Due to the method involved in exciting the photons in an LCD screen, the time lag between two images being displayed is quite high as compared to the CRT display technology. As consecutive images are not displayed quickly enough, certain details or even intermittent images are dropped by the control circuitry to catch up with the subsequent images, the result is jittering or "ghosting", as it is referred to. Ghosting results in a hazy picture with loss of details.

 

A TFT-LCD TV uses an array of special thin film of transistors (TFT) controlling and illuminating an array of an equal number of pixels. The transistors reduce the time taken to illuminate or shut off a particular pixel at a rate faster than the older LCD circuitry. This reduces the time taken to draw consecutive images as compared to LCD screen. A TFT-LCD television has at least a million pixels or 'mega pixels' for reproducing images. A TFT-LCD TV having a resolution of more than one mega pixels offers better sharpness as well as a larger viewable area. By dimensions, it measures similarly to a LCD screen in thickness.

 

• Micro-Display or Rear Projection TVs (back to top)

A rear projection TV is a cross-over between the LCD technology and the CRT method of displaying images. While integrating better picture quality offered by CRT technology, it allows for larger screen sizes offered by the LCD display technology. The display mechanism uses an array of pixels on a microchip much smaller in size and densely packed together for projecting the image. A powerful lamp then bounces light off or through this array of pixels onto a larger screen often via a magnifier lens or glass, finally reproducing this image. Such a digital television can reproduce high quality images as the actual image is created in a tiny array of densely packed pixels and also maintain higher refresh rates. The Micro-display TV sets are much thinner and lighter in weight as compared to a regular CRT television set but thicker and heavier than an LCD TV set.

 

• Plasma TV (back to top)

Much similar in functionality to the TFT-LCD technology, a Plasma TV screen uses an array of tiny pixels holding xenon or neon gases sandwiched between two sheets of glass. Each pixel acts as a cell holding the gas surrounded by electrodes on two sides. When a current passes between the two electrodes, essentially through the cell too, the gas molecules are excited. The molecules then release charged photon particles onto a phosphorous layer containing the three basic layers: Red, Green and Blue (RGB) for image reproduction. While all such activity is going on the inside of the screen between the two glass sheets, the photons upon hitting the colored phosphor layer illuminate the external surface and recreate the original image. This process results in an image with deeper and richer colors of up to 68 billion. The plasma technology can provide a contrast ratio as high as 10000:1.

 

2. Purchasing Criteria (back to top)

• Screen Size (back to top)

Deciding on the size (diagonal length of the screen measured in inches) of a set depends on the size of the room it will be placed in. Generally, a 12 foot by 16 foot room is large enough for a 42 inch television set. Most TFT-LCD television sets are available in sizes ranging from 20 inches to 90 inches. Micro-Display televisions are more like CRT sets, and require more floor space than a TFT-LCD or Plasma TV set. Plasma TV sets are thin enough to be hung onto walls like picture frames, thereby saving space and adding style points to your room. The older CRT television sets may be used for smaller room size measuring around 10 feet by 8 feet or so. For larger room sizes larger CRT TV sets are available, but the overall quality while viewing from a distance further than 7 feet may make the picture look grainy or dull as compared to the LCD or Plasma TV.

 

• Contrast Ratio (back to top)

The de facto standard supported by most LCD TVs is a minimum contrast ratio of 500:1. A lower figure would reproduce poor details, especially the darker shades. Simply put, a higher contrast ratio translates to darker blacks and brighter whites. A TV with a high contrast ratio, say 10000:1, would even show images present in darker backgrounds that may not be visible in one with a contrast ratio of 500:1. The contrast ratio should be considered while buying an LCD, TFT-LCD, Micro-display or a Plasma screen TV set.

 

• Native Pixel Resolution (back to top)

Picture resolutions can vary according to the screen size. An HDTV broadcast has a resolution of at least 1080 active pixel lines and a 16:9 wide-screen format. HDTV compliant TV ideally should support a minimum resolution of 1280 X 720 pixels. However, HDTV-compatible flat panel TV sets mostly offer maximum resolution support of 1366 x 768 pixels, most flat panel TVs now support this resolution. HDTV standard saw the introduction of Blu Ray and High Definition DVD technologies by Sony and Toshiba respectively. These standards broadcast HTDV images measuring dimensions of 1920 x 1080 pixels resolution. There are already some flat panel TVs supporting such high resolutions.

 

• Number of Colors (back to top)

Present day flat panel televisions reproduce billions of colors for rendering true-to-life picture quality. These televisions may support 20 billion to 550 billion distinct colors. Nonetheless, these billions of colors can only be experienced while viewing digital High Definition video only; regular broadcast video does not offer such a high quality signal, often rendering these amazing capabilities useless.

 

• Response Time (back to top)

The faster the screen is drawn or refreshed, the better the quality of displaying the visual in motion or high speed sequences. A lower response time or faster refresh rate means smoother video transitions and sharper images with reduced haze. A flat panel TV's response time is tested the most while viewing high quality DVD video. Response time is also vitally important when used for graphic-intensive gaming or when the TV is hooked up to a computer for using it as an alternative to a regular PC monitor.

 

• Dot-Pitch (back to top)

While choosing an LCD, TFT-LCD, or Plasma television, the dot pitch of the pixels should measure around 0.25mm to 0.30mm. A 'dot pitch' is the distance between two pixels of the same color; say red pixel from a triad of the red, green and blue pixels. The closer the pixels are to each other, the sharper the picture quality. Most flat panels support a minimum resolution of at least 720 dots per inch (dpi) and a maximum of above 1080 dpi. Also, larger the display, the higher would be the dot pitch. Choosing a high resolution TV set would allow for compliance with upcoming standards such as: HDTV, Ultra HDTV and Digital Video Broadcasts. It is important to note that due to the technology involved in Micro-Display TVs or the old CRT television set, there is no dot-pitch specification for these displays.

 

• HDTV-Compatibility (back to top)

HDTV, or High Definition Television, is an audio/video standard that defines the quality of motion picture. It is broadcast digitally in contrast to common analog broadcast formats such as: PAL, NTSC and SECAM. Separate tuners are built into the TV set. The screen redraw method in an HDTV broadcast is 'progressive' instead of 'interlaced' as found in older CRT based TVs. Sound channels are implemented using the Dolby Digital 5. 1 sound standard deploying full surround sound capabilities. Future standards such as Ultra HDTV and Digital Video Broadcasting are designed to deliver much higher quality of video signals compared to the current HDTV broadcasts thereby delivering extremely high quality entertainment to common households.

 

• PC Connectivity (back to top)

Most flat panel televisions provide a VGA connector and can be used as a big screen or high resolution PC monitor. Since these televisions support higher resolutions and lower refresh rates, they can ideally double up to be used as PC monitors. Some flat panel TVs even offer a 'TV-out' facility for connecting to projectors or even older CRT TV sets for scaled down regular viewing.

 

• Sound Quality/Technology (back to top)

With so much emphasis on screen size and resolutions, sound quality often takes a back seat while selecting a TV set. Most TVs come with built-in and often hidden speakers that provide amazingly high quality sound. However these TVs can be hooked up to home theater systems to complement their visual vividness TVs from prominent manufacturers offer various sound effect technologies such as SRS TruSurround XT and SRS WOW for providing 3D surround sound support.

 

• Price (back to top)

Variations of each of the aforementioned criteria will have a bearing on the price of your choice of television. Other specifications remaining constant, LCD TVs should cost significantly less than Plasma displays with Micro-Displays falling somewhere in between; CRT being the cheapest of them all. Screen size is another major price influencer; the larger the screen size, the lighter your bank balance! The buzzword in flat panel technology; 'HDTV compatibility' brings with it higher resolutions and contrast ratios and lower refresh rates and will therefore cost significantly more than non-HDTV TVs. Regular CRT televisions featuring HDTV compatibility are hard to find.

 

3. Making the Decision (back to top)

After deciding upon your requirements and preferences with regards to the various features mentioned above, you should compare various televisions that fill up those requirements at a comparison shopping site such as www.smarter.com. You may compare prices and features across models while also checking multiple suppliers on the Internet. Additionally, a nearby store may offer you a hands-on experience to check out picture quality and sound capabilities.

Chart out your specific requirements and look for models fulfilling those needs. Do not go in for a model that provides extra features that you're never going to use. The size of the TV should always be in proportion with the dimensions of the room it is supposed to be installed in. If watching regular broadcast television is its intended activity, contrast ratio and resolution could be compromised in exchange of a larger screen size; HDTV resolutions and features would not be used on regular TV viewing. For any hardcore gamer, good refresh rates and high resolutions are of prime importance. For smaller rooms, space efficient, wall mounting Plasma TVs can be a better alternative to space occupying Micro-Display televisions.

Buying a good TV requires investment of a reasonable amount of time in researching and evaluating the various contenders. The trick is to strike the perfect balance between price and functionality and the best way to begin is to find out exactly what your needs are. Hopefully, you now have more information to help make your purchasing decision more informed, now go find a great TV!