LCD vs Plasma TVs Buying Guide
- — 06 February, 2009 18:33
Jargon Busters: TVs
Analogue television: This is the regular TV that you have been watching for years. It is free-to-air and can be viewed on any CRT television so long as you have good reception.
Burn-in: This is like image persistence except that it is a permanent effect and cannot be removed. When plasma panels first hit the market in the 1990s this was a big problem. These days, most TVs don’t suffer from this issue.
Cables and connections: Before you step foot in the store you should think about the devices you want to connect to your TV and how they hook up. There are three common types of connections that you will probably come across: Composite, Component and HDMI.
Component: Is the next step up from Composite. It still has the red and white audio plugs but also has red, blue and green video plugs as well. This is mainly used on high-definition devices like the Xbox 360 but it can still be found on DVD players and other devices as well.
Composite: Has been around since the VHS and is often found on devices such as DVD players, video cameras and some older games consoles. It has red and white audio plugs and a yellow video plug.
CRT: CRT stands for Cathode Ray Tube but most people are used to just calling it the telly. The big heavy box that you've been watching for years is called a CRT television.
Digital television: To watch digital television you will either need to have a built-in digital TV tuner in your television or you will have to buy a set-top box. Digital television provides better quality picture and sound than analogue television plus it is capable of 5.1 surround sound. There are two types of digital television: Standard Definition TV (SDTV) and High Definition TV (HDTV).
DLNA: The Digital Living Network Alliance (DLNA) has developed a concept of wired and wireless interoperable networks as a way of sending information between your devices. For example, DLNA-compliant TVs are capable of streaming information from your network directly to your screen without a third-party device.
Dot-pitch: This is the space between each dot in an image. Generally speaking, TVs that have smaller spaces are better quality. If the space is too large, you will be able to see black lines across the entire image making it seem like you are looking at the TV through a flyscreen door.
D-Sub and DVI: These are the connection types that are used to connect a TV to a PC. D-Sub is the most common connection and is an analogue signal while DVI is high definition and capable of passing large amounts of data at one time. Either will suffice for a PC connection but DVI will always look much clearer.
HDCP: HDCP stands for High Definition Copy Protection and is the way that film studios stop piracy of Blu-ray films. If you plan to watch Blu-ray movies, make sure that the TV you buy supports HDCP because if it doesn’t the movies will not work.
HDMI: Uses only one black plug. HDMI isn’t as common as Component and Composite but it is the way of the future since many devices are starting to adopt it. It is used for high definition but it is also a good all-round connection type as only having one plug saves cable space. You should check how many of each connection type the TV you are looking at has and whether it will be enough for what you want to connect to it. Try to get a TV that has more connections than you need in case you want to add something later on down the track.
HDTV: This is digital television that uses 1080 lines of information to broadcast its pictures. The image quality of HDTV is far superior to SDTV and will look much clearer and crisper thanks to the extra lines of information.
High Definition: This term is used to describe any television with 720 or more horizontal lines of dots. It is also used to describe videos as well. For example, Blu-ray uses 1080 horizontal lines of information to make up its picture. Since this is over 720 lines it is considered high definition. High definition is mainly used for gaming on the Xbox 360 or PlayStation 3, when connecting a TV to a PC or when watching Blu-ray movies.
Image persistence: If you leave the same image on a plasma TV for too long, the TV can sometimes “remember” the image and will still show a faint outline of the image no matter what you watch. This is called image persistence and is a temporary effect that can be remedied. These days, most TVs don’t suffer from this issue.
LCD television: Unlike plasma panels, LCD televisions cannot produce their own light but instead use a lamp behind the panel to create the image. LCD, which stands for Liquid Crystal Display, works by adding electricity to a substance called Liquid Crystal to manipulate the passage of light from the lamps to the viewer. When there is no electricity running through the crystals, the light from the lamp can shine through it, because it is a see-through liquid. However, as soon as you add electricity, it becomes a solid and it blocks out all light, making it look black. This is the same technology as in a regular calculator but on a larger scale. When every little dot is displayed at the same time, you get an image which is then changed many times per second to display video.
LED: Stands for Light Emitting Diode. LEDs are beginning to be used in LCD TVs as a backlight which provides richer colours, better contrast and deeper blacks.
Motion enhancement: This comes under many names depending on the brand of TV. It is designed to make the image refresh at faster than normal rates to help smooth out jittering and make fast motion look more natural.
Native resolution: The native resolution is the maximum number of dots that a TV can produce. This number will appear as a length x height measurement of pixels, for example 1366x768.
Plasma panel: All televisions create images by drawing millions of tiny dots which then change as the image on the screen changes. In a plasma panel, each one of these dots has a little pocket of gas behind it (plasma) which is heated with electricity to produce UV rays. These UV rays then hit a layer of phosphor. Phosphor is a substance that lights up when you shine UV rays on it. Each dot in the image has its own little gas chamber which produces one dot of coloured light on the phosphor layer.
SDTV: This is digital television that uses 576 horizontal lines of information to broadcast its pictures. It is the standard digital television resolution and is commonly simply referred to as “digital television”.
Standard Definition: Television units or videos with less than 720 horizontal lines of dots are considered standard definition. Most standard-definition video has 576 lines of information and is mainly used for DVDs and television programs.