Shopping Guide: Televisions

1. Types of Televisions

a. Analog TVs: These are conventional Cathode Ray tube televisions that we have been watching for years. The signals are made up of radio waves which are translated by TV into video and sound. An analog TV cannot display progressive-scan DVD or HDTV. It can show only standard-definition programs such as those found on regular TV, cable, or satellite including digital cable or Dish Network. These TVs have some limitations:

• They display around 480 visible lines of pixels which put a limitation for higher resolution to fill a large television screen.
• A CRT TVs' electron gun refreshes only half the lines for each pass down the screen. On some TVs, this process (called interlacing), makes the picture flicker.
• Converting digital video to analog format lowers its quality.
• Bulky in size and heavy in weight. Need more space.

b. Digital TVs The term "Digital Television" is used for SDTVs, EDTVs, or HDTVs.

SDTV: A Standard Digital TV or SDTV is an analog television equipped with a built-in ATSC (Advanced Television System Committee) tuner to receive digital TV broadcasts. It will display a picture from these broadcasts, but HDTV programs would not look as good as on a true HDTV.

EDTV: An Enhanced Definition TV or EDTV is a TV that can display HDTV signals but lesser resolution than required to display the true quality.

HDTV: A High Definition TV or HDTV is a TV that can display standard TV, progressive-scan DVD, and HDTV signals.

• The picture quality is better.
• A digital signal can support a higher resolution, which enables larger TV screen with good quality pictures.
• The interlacing process of refreshing the picture can be replaced by progressive process, where entire picture is refreshed in every pass down the screen.
• It can support high-definition (HDTV) broadcasts.
• TV stations can broadcast several signals using the same bandwidth.

High Definition TVs or HDTVs have highest quality of resolution upto 1920 x 1080 as against the 704 x 480 or 640 x 480 in SDTVs, higher frame rate (rate of refreshing screen frame per second) upto 60 progressive as against upto 24 in SDTVs and an aspect ratio of 16:9 as against 4:3 in SDTVs.

However, even though a digital signal is of better quality than an analog signal, it may not be a high definition TV signal. HDTV signal standard is the highest of all the DTV standards. Seeing a high-definition picture and hearing the accompanying sound on a HDTV depends on whether the program being viewed is being broadcasted by the station as high-definition signal.

ii. CRT, LCD and Plasma TVs

a. CRT (Cathode Ray Tube) TVs use cathode-ray tubes to project the image on the screen and they have a bright, clear picture that can be viewed from any angle in the room.

b. LCD (Liquid Crystal Display) and Plasma TVs are becoming popular for their slim dimensions and large screen sizes. While LCD TVs work like the screen of a laptop, Plasma TVs operate by illuminating thousands of tiny fluorescent lights to create the image. These TVs generally have poor black level (ability to display black color) vis-a-vis CRT TVs.

2. Features and their meaning/importance

It is generally thought that bigger is better when it comes to TV screen size but this is not always true. A large TV in a small room will look awkward and also make watching TV uncomfortable. Similarly, a too small TV in a normal room will be a strain on eyes to make out the details. Taking the right decision about the size of television is, therefore, the first step in TV shopping.

The size of a TV is measured diagonally across its viewing screen. The correct size of screen will depend upon the size of the room in which the TV will be placed and the distance of the couch or sofa to view the TV. The size of TV can be estimated by mentally placing the TV in the room.

A TV (other than a flat panel TV) usually gets bigger in size and heavier as the screen gets larger. Flat-panel (LCD and Plasma) TVs are growing in popularity because a larger screen size can be accommodated in a smaller space or the TV can also be hanged on a wall. Ventilation of the place where TV is to be installed is also important as TVs generate heat, when in use.

TVs are mostly available in two screen shapes. The most familiar have width to height ratio of 4:3 and the others called wide screen TVs have a width to height ratio of 16:9. Wide screen televisions take the same shape as many movies and cost more per square inch of screen than the standard TVs. As most people watch more of regular TV programs than DVDs and movies, 4:3 sets are the more popular choice. While a 4:3 Screen shape TV may show black stripes on top and bottom of the screen while viewing a movie, a 16:9 screen shape TV may show black stripes on both sides of the screen while viewing a normal TV program. Some manufactures remove the black stripes by stretching or cropping the picture to fill the entire screen.

These are used to get the best resolution from DVDs or other digital sources. The common types of comb filters include two-line, three-line, digital, and 3D YC varieties. They provide incremental improvements in performance.

This feature enables control of gray color. Natural gray is ideal for getting natural tone in the pictures. However, most TVs have a setting of bluish gray to make the picture brighter.

In 4:3 aspect ratio TVs, this feature helps to resolve some discrepancies between a DVD's resolution and the TV's resolution and helps in getting closer to a film-like look without going for a 16:9 television.

This feature allows watching a second broadcast in a small window on the screen while watching something else.

This is an add-on for getting theater like sound without going for a full sound system. However, no TV can compete with a dedicated audio system.

This feature allows parents to lock out programs based on their contents of violence and/or sex with passwords so that children are unable to view them.

Many TVs now come with universal remotes that can control other audio/video gears like a cable or satellite box, DVD players, VCRs etc., usually of the same brand.

Connecting panels on front and rear form an important part of a TV because it is an important part of home entertainment. You will be required to connect other devices like DVD player, VCR, Video game console, Headphone, Microphone etc. to make full use of the TV. Convenient connecting panels on front and back of the TV add to the ease of use of the TV.

Some TVs offer tuning, volume, contrast, brightness and other controls both on the TV and the Remote and some TVs offer many of such controls only on the Remote through onscreen setting menu. Availability of all major controls on TV enables you to control/adjust setting of the TV even without a remote.

You may have a look on the terms of warranty offered by the manufacturer to check for any restricting clause(s). Location of manufacturer's service centre at or near your place will help in getting the TV serviced quickly in case of any trouble/fault.

The above information may be used as a guide to match your budget with the type of TV and features you want have. Many manufacturers come out with different names for different features and go on adding new features to their products. You may go through their advertisements, brochures, read reviews of experts etc. to focus on the type, make and model of your new TV. Wish you a happy buy and lots of entertainment from your new TV.