HDTV Television

In the first in a series of high-definition buying guides, we’re unsurprisingly starting with HDTVs. High-definition puts some restrictions on the type of screen you can use, which has created some confusion.

So, if an HD Ready logo just isn’t enough explanation then read on for some basic tips to buying an HDTV:

Techno types

HDTV’s generally fall under two types of technology - LCD and plasma, although oversized rear projection DLP models are also available. It used to be that smaller screen sizes were reserved for LCD while anything over 37in saw you entering plasma territory. But, LCD technology has advanced and become the dominant technology across all screen sizes - probably because they are cheaper to manufacture.

LCDs typically feature brighter images with more impressive resolutions and lower power consumption. High-definition images appear incredibly detailed but backlighting tends to bleach black levels and subsequent contrast suffers.

Plasmas offer deeper black levels with a wider contrast range, more natural colours and cohesive movement but can suffer from dead pixels and screen burn. It comes down to personal choice but, while plasmas are preferred by the purists, fewer screens are being produced nowadays.

Size matters

The arrival of flat screen displays with space saving designs has led to an increasing appetite for larger screen sizes. The average screen size in the UK has risen to around 32in but forecasts predict that 42in will eventually become the most popular size.

Generally, the bigger the picture, the better the viewing experience ??“ but screen size should be dictated by your room and you’ll need enough space between your seat and the screen to appreciate the best picture quality - and avoid living under a widescreen shadow.

As a benchmark, a 42in screen requires a distance of between 1.5m - 3m while larger screens need to be at least 2m away from your seated position. Larger screen sizes can create a greater cinematic experience but they can also expose picture flaws, especially if you’re not watching high-definition images.

Talking ’bout a resolution

A screen’s native resolution defines the total number of pixels used to display a picture - the absolute limit of what the screen can display. The higher the resolution, the more detailed and precise the images appear.

To display typical high-definition images the screen’s resolution needs to display at least 720 vertical picture lines in widescreen ??“ standard-definition uses only 576 lines. Most standard flat screens use a WXGA resolution (1366×768) that will display common 720p and 1080i signals used by high-definition broadcasts ??“ 1080i signals are slightly downscaled to fit but the effect is negligible.

However, to display the latest 1080p signals used by next-generation Blu-ray and HD-DVD players or PS3 games consoles you’ll need a screen with a so-called ‘Full HD’ (1920×1080) resolution. These screens are still relatively scarce and expensive but prices are falling and they do provide future-proof compatibility.

Get connected

Although some devices such as the Xbox360 can use analogue component connections to deliver high-definition signals, it’s practically essential that your screen features a digital video input with HDCP protection to prevent illegal copying of high-definition content.

Usually, this is an all-important HDMI input, which can be used to carry high-resolution images and sound using a single cable. The connection has evolved since its inception with several variants.

Multiple HDMI inputs allow you to connect several HD devices such as an HDTV receiver, disc player and games console, simultaneously without having to frustratingly switch cables. Alternatively, you can use a separate HDMI switching box or an AV receiver that features video switching ??“ all devices can be connected to the receiver, which then switches them via a single output to your screen.

Sound wise

Flat screen HDTVs usually feature integrated speaker systems but they are restricted by the small size of the cabinets. Some are better than others and features such as virtual surround modes and bass enhancers can be useful but images this impressive deserve to be accompanied by an external sound system ??“ so screens with digital audio outputs are helpful if you have a home cinema system.

Testing times

It’s always useful if you can see an HDTV in action before parting with any money - but, beware of consumer electronics showrooms. Retailers often display screens under bright lights, exaggerate the picture settings and use flawless animated films to attract customers.

If it’s possible, ask if the lights can be dimmed then adjust the settings and picture modes personally using your a disc that you’re familiar with ??“ or even a calibration disc such as Joe Kane’s Video Essentials.

Buying online can offer better prices with the same warranty but you don’t get to physically experience the product and returning goods is often your responsibility and cost.