Television Buying Guide 6

Inputs and Outputs
One of the most confusing items on a television spec sheet is the types of inputs and outputs the television can accommodate to get connected to other equipments. The following is a snapshot of different types of connections and their quality.



Name: RF (Radio Frequency)
Sources: Antennae, VCRs, cable and satellite boxes
Quality: Lowest, highest for HDTV tuners



Name: Composite Video
Sources: Cable and satellite boxes, VCRs, DVD players, game consoles
Quality: Low



Name: Component-video
Sources: HD cable and satellite boxes, DVD players, HDTV tuners, Blu-ray and HD DVD players, game consoles, other HD sources
Quality: High



Name: RGB
Sources: Computers, video processors
Quality: High



Name: FireWire
Sources: Some HDTV tuners, D-VHS VCRs
Quality: Highest (digital)



Name: DVI-D with HDCP
Sources: Computers; older HD cable and satellite boxes, HDTV tuners and DVD players
Quality: Highest (digital)



Name: HDMI
Quality: HD cable and satellite boxes, DVD players, HDTV tuners, Blu-ray and HD DVD players, game consoles, computers, other HD sources
Quality: Highest (digital)

Television Buying Guide 5

Almost all HDTVs sold nowadays are wide-screen televisions, which means the aspect ratio of the television is 16:9 compared to standard definition televisions which are 4:3.


Black Bars and Unused Screen
The problem with the aspect ratio is that most of the television shows are still broadcasted in 4:3 format. To view them on a wide-screen television without stretching or cropping the picture, you have to waste a portion of the screen by putting bars on either side of the image. Conversely, if you have an old 4:3 television, to watch a wide-screen show you will have to tolerate two bars above and below the picture.


Wide-screen Televisions and 4:3 programmes
If you do not want to waste your wide-screen space on empty bars, listen to a good piece of news. All wide-screen televisions can stretch, crop, or zoom 4:3 programmes to fit the screen. These methods distort the image to some extent, but it is a lot better than having two bars on either side of the screen.

Television Buying Guide 4

Regular Television Programmes on an HDTV
You may be disappointed in your HDTV the first time you see a programme on it. That may be because you are watching a standard definition channel. Regular television programmes can look very bad on an HDTV compared to high definition programmes. An HDTV is larger and sharper and shows more of the flaws of standard definition broadcasting.

DVD Programmes on an HDTV
Regular DVD programmes look very high-quality and spectacular on an HDTV and most people are quite satisfied with them. Many DVD players and all Blu-ray players have a built-in upconversion unit that converts DVD programmes to high-definition. However, in most cases the difference would be subtle.

HDTV is Tomorrow
Buying an HDTV is a smart move, as you can be fairly sure that they will not become obsolete at least for a few years. Of course, new technologies emerge every now and then but nothing on the scale of shift from SDTV to HDTV is likely to happen for a long time. Almost every HDTV is equipped with an HDMI input that can accept copy-protected signals.

Television Buying Guide 3

Air Antenna Receivers
The law requires most television sets sold after March 2007 to include a built-in tuner that can receive high-definition programmes broadcasted on air by a simple antenna. If the television is not equipped with such a tuner, an external tuner or box is required to watch these programmes. So most televisions (not monitors) sold after that date, must comply with the aforementioned law to accommodate DTV (Digital Television) transition.

Digital Television Transition
A bill has been passed by the congress that requires over-the-air stations to switch to digital broadcasting between 17 February and 12 June 2009. After the final date, televisions with old NTSC tuners will be unable to receive over-the-air programmes. So many people who use “rabbit ears” or rooftop antenna and their televisions do not have a tuner, will stop receiving broadcasts. As a result, a subsidy program has been created which provides $40 coupons (limit of 2 per household), that can be used toward a digital converter box.

Television Buying Guide 2

Television Types
Televisions can be categorized into four different groups according to what type of signal they can accept and what picture quality they can show:

1. Analog
2. SDTV (Standard Definition Television)
   
3. EDTV (Enhanced Definition Television)
4. HDTV (High Definition Television)

Analog
This type of television can not display HDTV programmes. It can only show standard definition programmes found on regular television, cable, or satellite channels.

SDTV
This type of television (standard-definition) is basically an analog television plus a built-in ATSC tuner. Therefore, it can receive digital television broadcasts. It will display a picture from these broadcasts, but HDTV shows will not look nearly as detailed as they would on a true HDTV.

EDTV
This type of television (enhanced-definition) is usually a type of television that can display HDTV signals but doesn't have enough resolution to really do them justice. Most often it applies to plasma televisions and denotes 852×480 resolution.

HDTV
High-definition televisions, or HDTV, can display standard television, progressive-scan DVD, and HDTV signals. They are by far the most common type of digital television. Nearly every plasma, LCD, and rear-projection television is an HDTV.

Television Buying Guide 1

Soon after posting the previous notes, I received feedback from several people to write in simpler and more practical terms and also shorter; this brings me to the following series of posts which are a short and simple guide to buying a new television.

Introduction
Televisions are expensive equipments, but price-wise they can be put into a few categories. Here comes a small chart that can match your funds with the types of television you can actually afford, which might be far from what you have pictured in your dreams.


Selecting the best size
Now that you have narrowed down your budget, you need to decide the proper size for your television. Obviously, larger screens cost more, but television should have the right size for the room in which you are intending to put it. Here is a small chart that gives the proper distance from your television.

Generally, 30" and smaller displays work great in bedrooms but they are too small for the living rooms. Larger displays are suitable for the whole family to enjoy but they would be too much for small bedrooms. If the television is put in an entertainment centre, make sure it has enough room for ventilation. Nowadays, many televisions come with dedicated stands that can even accommodate other components such as cable boxes and DVD players.

DLP (Digital Light Processing)

Digital Light Processing (DLP) is a technology patented by Texas Instruments, a technology used in projectors. This technology is used in front projection and rear projection televisions. It is also one of the leading technologies used in digital cinema projection.

Digital Micro-mirror Device
In DLP projectors, there is an array of small mirrors (microscopic) that are positioned on a semiconductor chip called Digital Micro-mirror Device (DMD). Each mirror produces one or more pixels in the image. The number of mirrors is the maximum resolution attainable by the display, e.g. 800×600, 1,204×768, 1,280×720, and 1,920×1,080. The mirrors can either pass the light through the lens (On) or completely block the light (Off) and they can switch positions quite rapidly. Controlling the on and off times can produce different shades of grey.

How colour is produced in DLP projectors?
There are three methods available to DLP projectors for colour production:

• Single-chip DLP projectors
• Three-chip DLP projectors
• Sequential illumination by three LEDs (light emitting diodes) (still in development, only in select Samsung models)
  

Single-Chip Projectors
In single-chip projectors, colours are either produced by a colour wheel between the lamp and the DLP chip or by using individual light sources to produce primary colours (e.g. LEDs).

Three-Chip Projectors

In three-chip projectors, a prism is used to split light from the lamp and each primary colour is projected to its own chip, then recombined and routed out through the lens. These are used in higher end projectors. They are capable of producing 35 trillion colours. It is suggested that the human eye can detect around 16 million colours


Digital Cinema
DLP is the current market-share leader in professional digital movie projection, largely because of its high contrast ratio and available resolution as compared to other digital front-projection technologies. As of December 2008, there are over 6,000 DLP-based Digital Cinema Systems installed worldwide.

Pros

• High resolution images (up to 1,080p)
• Perfect geometry and excellent greyscale linearity achievable
• High contrast
• No possibility of burn-in
• DLP rear projection televisions are considerably cheaper than LCD or plasma flat-panel displays and can still offer 1,080p resolution
• DLP Projectors can process up to 7 separate colours giving them strong colour performance
• DLP projectors do not suffer from “Colour Decay” often seen with LCD projectors in which the image on the screen turns yellow after extended periods of usage
  

Cons

• Not as thin as LCD or plasma flat-panel displays
• Dithering noise may be noticeable, especially in dark image areas. Newer (after 2004) chip generations have less noise than older ones
• Lower viewing angle than direct-view technologies such as CRT, plasma, and LCD