Electronics

Television buying guide

Updated 29 Mar 2011

Introduction

LED, LCD, plasma, projectors ... the choices are daunting. Our guide compares the options.

In this free guide we compare the various types of television: CRT, LCD, LED, plasma, rear projectors and front projectors. Plus, we explain the mysteries of digital, analogue and HDTV and look at connections and set-adjustment.

And consumer.org.nz members can check out our test results and best-buy recommendations for LCD, LED and plasma TVs.

The options compared

Your choice of television will depend on price, size, design and technology. Here are the pros and cons of each option. Note that prices are a moving target - they change all the time!

Liquid crystal display (LCD)

Price range: $350 to $6000
Common sizes: 17 to 55 inches

How it works:
LCD (liquid crystal display) is the technology used in slim-line computer screens. The image is made up of dots (pixels) which are tiny blinds that can be opened or closed to allow the light behind them to come through. LCD technology is also used in rear-projection TV sets.

Pros:

Very good picture quality.
Thin and light.
Wall-mountable.
Screen is not reflective.
Very low risk of burn-in of static images compared to plasma.
Reasonably low running costs in smaller sizes - similar to a CRT TV of the same size.
Some can double as a computer display.

Cons:

Images can dim as you angle away from the centre of the screen.
Greater risk of motion blur than plasma (but not extreme).
Contrast usually not as good as plasma.

Our verdict:
LCDs are the new benchmark TV. They're now much cheaper and have much better quality than earlier models.

For more information, see our full report on LCD and plasma televisions.

Light emitting diode (LED)

Price range: $1200 to $4000
Common sizes: 32 to 60 inches

How it works:
Despite all the marketing hype surrounding LED TVs, they’re not a different "type" of TV technology. An LED TV is simply an LCD panel that uses different backlighting. Standard LCD TVs use lamps called cold-cathode fluorescent lights (CCFLs). LED TVs use light emitting diodes (LEDs) for backlighting.

There are two types of LED backlighting. The usual one is “full array” where LEDs are lined behind the LCD panel. The other is "edge-lit", where the LEDs are positioned along the four edges of the screen and project light inwards. Edge-lit TVs can be thinner than full array models but can also have less consistent backlighting – for example, the edges of the screen can seem brighter than the middle.

The higher price tag and newer technology of LEDs doesn’t necessarily mean a better picture. Our recent TV tests found some LED models ranked at the top of the table while others were near the bottom, beaten by standard LCD models.

Pros

Much thinner and lighter than standard LCD models.
More energy efficient than standard LCD models and much more efficient than plasmas.
Very good picture quality – some are superior to standard LCD models.
Screen is not reflective.
Very little risk of burn-in of static images compared with plasmas.

Cons

Generally more expensive than standard LCDs of the same size.
Images can dim as you angle away from the centre of the screen.
The same risk of motion blur as standard LCDs and usually more than plasmas.
Some (but not all) can have very poor sound quality.

Plasma

Price range: $650 to $5000
Common sizes: 42 to 60 inches

How it works:
Plasma is an array of very small dots called pixels, each of which is made up of a red, green and blue phosphor cell. The phosphor cells are filled with a gas - usually xenon, neon or argon. When an electric current passes through the gas, it's excited into a plasma state (hence the name) and the gas emits ultraviolet light which in turn causes the phosphor to glow.

Pros:

Very good picture quality.
Negligible risk of motion blur.
Usually has the best contrast and brightness.
Can be viewed from any angle without losing quality.

Cons:

Not available in smaller sizes below about 37 inches.
Usually use more power than LCD.
Generates lots of heat and may have fan noise.
Can suffer from burn-in of static images.
Can be very costly to run, especially above 50 inches.
Relatively heavy, and wall-mounting can be expensive.
Shiny screen can be reflective.
Has to be kept upright for transport.

Our verdict:
Large plasma screens are now as reliable as LCDs and match their picture quality. They're also similarly priced.

Cathode ray tube (CRT)

Common sizes: 14 to 32 inches

How it works:
CRT (cathode ray tube) is the old conventional TV screen. It creates an image by firing electrons at the screen, which is coated with a fluorescent material. This technology has been around for 75 years.

There are no new CRTs in stores any longer and they are extremely cheap second-hand. The price of LCDs has come down to the point that CRTs are no longer a much cheaper option.

Pros:

Reliable, proven technology.
Generally very cheap.
A wide range of sizes are available.
Cheaper to run than plasma screens.
The best have very good picture quality.

Cons:

Larger sizes are bulky and heavy. No genuinely large screens (over 32 inches).
Most have a 4:3 aspect ratio rather than the newer 16:9 widescreen ratio.
Not capable of displaying a high definition (HD) picture.

Our verdict:
New CRT TVs are no longer available in stores. If you're in the market for a new TV, we recommend purchasing a high definition set.

Rear projector

Common sizes: 42 to 60 inches

How it works:
The image is projected through lenses and mirrors from the back of the set onto a screen at the front. Available in four types: LCD, DLP, LCoS and CRT. There are no new rear projection TVs in stores nowadays as large LCD and plasma screens can be produced more cheaply.

Pros:

Big screen.

Cons:

Work best in darker rooms.
Heavy and fragile (many need regular lamp realignment).

Our verdict:
Rear projection TVs have been made obsolete by large LCD and plasma TVs. Ongoing maintenance costs can be considerable.

Front projector

Price range: $600 to $15,000
Common sizes: 60 to 150+ inches

How it works:
The machine beams an image onto any surface you point it at - a wall or screen. Available in three types: LCD, DLP and LCoS.

Pros:

Biggest screen size of all.
Many high definition models available.
Light and portable.

Cons:

Don't have a built-in TV tuner or built-in audio.
Can be difficult to set up.
Can have noisy fans.
Cheaper models may not be ideal for watching in a lit room.
Lamp replacement can be expensive.

Our verdict:
Not ideal as an everyday TV but magic for movies and sports - front projection's the nearest thing to a cinema experience at home. They usually work best in a dedicated, dark media room, and require additional sound equipment (like a home-theatre system). Ongoing maintenance costs can be considerable.

Size and shape

Size

TV screen size is measured diagonally across the face of the screen. It used to be measured in inches but then changed to centimetres viewable (cmv). This should represent the picture size you can see to within half a centimetre. But with the advent of LCD and plasma screens, the clock has been wound back to the 1960s, and the TV industry is using old fashioned inches again.

Here's how the sizes compare.

Inches	cmv
14	34
15	36
17	43
20	48
21	51
25	59
26	66
29	68
32	80
34	85
36	90
37	93
38	96
40	101
42	106
50	127

Optimal viewing distance

As a general rule, the ideal viewing distance from a normal standard definition TV is around 5 times the diagonal screen size. So for a 68cmv (29 inch) set that's around 3.5 metres. For a widescreen TV it's about 3.5 times the diagonal size.

For high definition TVs the closest you should sit is 1.5 times the diagonal screen size for a 1080i screen, and 2.5 times for a 720p screen. So for a 106cmv (42 inch) screen with 1080i resolution you can sit as close as 1.5 metres without seeing pixels. For the same sized screen in 720p resolution you need to be 2.5 to 3 metres away.

Conduct your own test in the store with rough measurements of where you'll sit and where the TV is likely to be positioned. Move closer and further away from the TV to see if and where the picture loses quality.

Widescreen TVs

These screens have a width-to-height ratio of 16:9 - similar to that used in movie theatres. Movies on DVD are usually in 16:9 and an increasing number of TV programmes are shown this way.

Although the screens are wider, they are not as high as you might expect. For example, if you want to replace a conventional 68cmv set with a widescreen model in a similar size, the choice isn't easy. A 76cmv widescreen set will show you pictures that are shorter by about 3.5cm than those on your 68cmv set. Smaller 66cmv sets are only just wider than a normal 68cmv set, and very much shorter.

What you really need is a 91cmv widescreen set, but that's not a common size ... Even the next size up, 93cmv (37 inch) is relatively rare and a little expensive.

Common 4:3 sizes and nearest widescreen equivalents:

34cmv = 43cmv (14 inch = 17inch)
51cmv = 66cmv (21inch = 26 inch)
59cmv = 80cmv (25inch = 32 inch)
68cmv = 93cmv (29inch = 37inch)

Connections

TV sets don't always come with the right connections. Check carefully and talk to the retailer about the best setup for you. Make sure you get this sorted before you take delivery.

For a top-quality picture, always use the best available connection. Ideally, this would be a high definition signal via DVI or HDMI to a high definition screen.

These are the connectors you may find on your TV set, starting with the most basic:

Connection type	What it looks like
RF connector
This used to be the only connector on a TV. If that's all you have, then connecting to a DVD player or games machine usually means getting an RF adaptor. Connecting to an HD source is probably out of the question.
Composite video (AV)
Composite video input is the standard system - most post-1995 screens have at least one set of these. Composite video uses two (video and mono sound) or three (video and stereo sound) cables. The brightness and colour signals are combined into the single video signal (yellow RCA connectors); there are also mono or stereo audio channels (red and white RCA connectors).
S-video
This offers a better picture-quality than composite because the brightness and colour signals are kept separate - but you'll need separate audio cables because S-video doesn't carry sound. S-video can be identified by a small round four-pin plug (mini-din).
Component video
This is the best picture-connection option for conventional TV sets, but it's not always available. LCD and plasma sets almost always have this connection, and some can even accept a high definition picture this way. It separates the picture into brightness and colour signals, and so provides better quality. Three video (red, blue and green RCA connectors) and two audio cables (red and white RCA connectors) are required.There are two component options: RGB; and Y,Pb,Pr. RGB is the type of signal generated by a professional video camera, and is not so common. The more common version is Y,Pb,Pr, which is encoded so that it uses less of the signal bandwidth. The one you use may be determined by the connections on your DVD recorder and screen. (You can't send an RGB output to a Y,Pb,Pr input or vice-versa.)
SCART
This stands for Syndicat francais des constructeurs d'appareils radiorecepteurs et televisieurs, and is also known as a Euroconnector. It's a single-plug 21-pin connector for analogue video and sound. It can carry S-video, RGB component video, composite video, and audio channels.
DVI (digital visual interface)
This is a high definition connector for video and is usually found only on plasma or LCD screens. It can carry digital and analogue video signals to a screen capable of displaying them. It's compatible with HDCP.
HDMI (high-definition multimedia interface)
This is an all-digital connection for both video and sound in one cable. It's not usually fitted to conventional tube TVs, but is a standard - and primary - connection on high definition TVs. It's HDCP compatible.

How to adjust your set

Your brand new TV may not be adjusted well from the factory. When we test televisions we often find they are delivered with settings that are nowhere near realistic. They have too much contrast, colour and sharpness. Here's how to adjust a TV to the right settings.

1. Choose a local channel, preferably with a well-lit outdoor scene. Turn the colour control right back so you have a black-and-white picture.

2. Adjust the contrast and brightness to get the best-looking black-and-white picture possible. Look for a smooth series of greys between the full black and the full white. Contrast adjusts the difference between black and white, and brightness adjusts the overall picture. Too much contrast will remove the greys. Too much brightness will make black into grey. Start adjusting with both controls at their midpoint.

3. Change the channel to a presenter. Slowly bring in the colour until the skin tones look natural.

Note that the sharpness control was introduced to aid VHS tape replay quality. It is misnamed, having nothing to do with the picture focus, and is not useful for normal broadcast or DVD viewing. Keep it toward the lower end of its range.

Adjust the sound by experimenting with the controls. Start with on/off controls like bass boost set to off, and variable controls like bass and treble set to the midpoint. Make small adjustments one control at a time.

Where's my widescreen?

Have you got a widescreen TV but seem to be missing the edges of the picture? Here's how to fix it.

First make sure your TV is set to the widescreen 16:9 aspect ratio. You should be able to do this using the menus on the TV or remote control - consult your TV's instruction manual.

If you're still missing the edges of the picture it's most likely because you have a Sky TV or Freeview decoder that is set to display a 4:3 aspect ratio rather than 16:9. You'll be amazed at how much more picture you get by doing the following:

Sky TV

Using your remote, turn on a Sky channel and press the select button (the oval button inside the four arrows).
Using the arrows, select the "spanner" icon then "Advanced Setup" using the same oval button.
Enter your four-digit pin number, press select, and then select "TV Setup".
Select "16:9" from the menu, press select and then press the "Go Back" button on your remote twice to return to the channel.

Freeview

Select menu, and then either "Installation and Settings" or "System Configuration" depending on the type of set-top box you have.
Then select "Output Settings" or "System Setup" depending on the set-top box you have.
Change "Aspect Ratio" to "16:9"

These instructions and more are available at the Sky TV and Freeview websites. If you're still having problems, get in touch with either and ask for assistance.

Remember that not all TV programmes were made or are available in the 16:9 format. You'll notice big black vertical borders on your 16:9 display when these 4:3 programmes are displayed. And since some movies were not filmed in the exact 16:9 format you may still occasionally get small horizontal borders as well. Don't worry, this is normal.

High definition television

High definition (HD) is a high-resolution form of digital television. Many more lines and pixels make up the picture, giving a clearer, more-detailed and crisper look than standard definition.

HDTV sets

To get the benefit of high definition pictures, you need an HDTV set to view them on.

HDTV sets come in formats of 720p, 1080i and 1080p. The number indicates how many horizontal lines are in the picture - so a 1080i has 1080 horizontal lines. By comparison, standard definition (SD) screens have only 576 horizontal lines.

High definition screens also use many more pixels to make up the picture. A 1080i TV can show around 5 times as many pixels as a similar-sized SD screen.

But what really counts is the letter. This tells you the type of technology used.

"i" stands for interlaced scan. This draws the picture across the screen in two passes, alternating between odd and even lines. Only half the picture is displayed at any one time - but it happens so quickly that the human eye sees one continuous picture. CRT TVs use this method.
"p" stands for progressive scan. This delivers the picture to the screen in one pass, meaning the whole picture is on screen at all times. Some 1080p models have effectively twice the picture detail of a 1080i, because the all of 1080p's picture is there at any one time.

A "p" screen produces a smoother picture with less flicker, so it's usually considered better than an "i" - especially for fast moving action such as sports. Even though it's got fewer lines, a 720p can give you better sports viewing than a 1080i.

Name	Resolution
1080p	1920 x 1080
1080i	1920 x 1080
720p	1280 x 720
SDTV	576 lines

Note: 1366 x 768 screens are slightly enhanced 720p models.

Screen size
The size of the screen is important too: a big screen with the same resolution as a smaller one will have bigger pixels. Why does this matter? Because you don't want to be aware of the pixels. They make the picture look "grainy".

As a general rule, you shouldn't see pixels on a 42 inch, 720p provided you're sitting just over 3 metres away. Having a 1080i or 1080p screen of the same size would allow you to sit around 1.6 metres from the screen. But if you normally sit around 3 metres back anyway, the higher resolution will have no real benefit.

HDTV Broadcasts

Picture quality doesn't just depend on the type of screen you have - source and connections are just as important. If you feed a low-quality analogue broadcast into your HDTV, you'll get a low-quality analogue image. For the best picture quality you need an HDTV signal transmitted directly to an HD screen.

Here's a rundown of HD and SD sources:

Broadcast TV (including much of Sky's satellite service) is usually SD. The motion blur you see in fast-moving action will usually be from the TV signal, not from your TV set.
Freeview terrestrial shows some content in HD but a greater amount in SD. The satellite service doesn't show HD yet.
MySkyHDi shows a lot of sport and movies in HD, but most other channels are in SD.
DVDs are SD but you can make them look better by connecting with component video or HDMI cables, rather than the more common (red, white and yellow) composite cables. (See Connections for more information.)
Blu-ray movies and discs are full HD (1080p) resolution.
Game consoles are mostly HD. The PlayStation 3 supports full HD (1080p) and the Xbox 360 supports up to 720p and 1080i. The Nintendo Wii is SD.

Digital television

Digital TV means the television signal is broadcast in a digital format (such as Sky Digital). Digital TV is not necessarily high definition (HD) TV – HDTV is just one form of digital television.

There are three digital options currently available:

Sky TV's pay-digital service via satellite.
Telstra Clear's cable pay-TV digital network, re-broadcasting Sky in Kapiti, Wellington and Christchurch.
Freeview digital satellite and land-based services

Picture quality on older TVs

Digital TV will show on any old TV with the aid of a decoder, although it won't be in HD. But what about the quality?

Unlike analogue, digital transmissions don't suffer from interference or ghosting (unless the weather is foul, when satellite transmissions can break up or cease altogether from "rain fade"). So all the information gets through, which can mean a potentially better-quality picture.

But to show on an old analogue-based TV, the decoder has to convert the digital transmission to analogue (see Analogue vs digital below), and this can mean some loss of quality.

Using the best-available decoder connections will mean your analogue screen can get a slightly better picture from a digital broadcast. But for the best picture quality, you need a high definition signal direct to an HDTV screen.

Analogue vs digital

Analogue TV is now old technology – it was first invented in the 1930s – and its resolution is limited by the number of horizontal scanning "lines" the TV can show.

New Zealand analogue television is broadcast using the PAL (Phase Alternate Line) video format, also used in the UK and Australia. This has a higher resolution than NTSC (National Television System Committee but also known as Never Twice the Same Colour), which is used in the US and Canada.

PAL has 625 lines, but only 576 are actually used. NTSC uses 480 lines out of a possible 525. Digital television has the potential to show up to 1080 lines (at 720 or more lines, it's called HDTV).

Many screens accept either PAL or NTSC, and VCRs or DVD players can usually play both types. So if someone sends you an NTSC tape or DVD, chances are it will play okay, unless it is the wrong zone for your DVD recorder.

The end of analogue
Analogue TV is how we have received free-to-air television broadcasts since the 1970s. But this is now being replaced with Freeview digital TV.

The analogue signal will be switched off between September 2012 and December 2013.

If you want to continue receiving free-to-air TV in the future (and haven’t got Sky), you have to adopt Freeview. (See our Guide to digital TV for more information.)

Buzzwords

Here are definitions of some of the terms you may come across when you're looking for a new TV.

Analogue TV means the television signal is broadcast in an analogue format (such as non-Freeview free-to-air New Zealand channels).
Digital TV means the television signal is broadcast in a digital format (such as Sky Digital or the Freeview satellite digital service). Digital does not mean HD (high definition). See Digital television for more.
HDCP stands for High-Bandwidth Digital Content Protection. It's a security coding system used to prevent movies being copied.
HDTV is a high-resolution digital system for broadcasting TV. See High definition television for more.
NTSC is a video format used for SDTV television broadcasts, videos and DVDs in the United States, Canada, and Japan.
PAL is a video format used for SDTV television broadcasts, videos and DVDs in England, Australia and New Zealand.
SDTV is a low-resolution analogue or digital system for broadcasting TV.