FROM DESPAIR...TO HERE!

This entry is written with the UK consumer in mind (due to the limitations of the author's knowledge rather than any kind of prejudice!). Some of the article may apply to other countries and appeal to other nationalities, but if anyone has anything to add on their own television systems, please contribute to the conversations!

There are a few footnotes. They are simply there to give definitions, or if specified, technical details.

HELP IS AT HAND

Gone are the days when shopping for a TV was simple. Nowadays we are confronted with a barrage of different options. The choice has become immense. New technologies have hit the marketplace, confusing information is abound, making the choice quite painful. It is easier to close one's eyes, spin around three times and point: 'I'll have that one'! This guide entry is intended to cut through the myths, unravel the jargon and make the options available much clearer.

BIGGER IS BETTER, OR IS IT?

So the decisions to face:

These questions shall all be answered in good time, but first: -

WHY WIDESCREEN?

In one sentence: to replicate the human field of vision. Traditional TV screen sizes were of the ratio 4:3. This pertains to the ratio of the width to the height, for instance if the height is three inches, the width will be four inches. The ratio is maintained, no matter how big the screen.

Our view of the world is very similar to the scale of a modern 16:9 widescreen television, which has become the agreed standard ratio (aspect ratio) for widescreen televisions. For cinemagoers widescreen is nothing new. Before I give a potted history of widescreen, I shall give a quick rundown of aspect ratios most commonly used in film and television terms. Film ratios are often expressed as n: 1, whereas TV aspect ratios are denoted by whole numbers. This can be a little confusing but is mathematically sound: -

The majority of films for cinema presentation are produced in a widescreen format. This is known as cinemascope, with a ratio of 2.35:1 (see table above). There are other widescreen film formats in use, but 2.35:1 has become a relative universal standard, especially for Hollywood film presentations. Anamorphic lenses were developed during the 1950's which squeezed the image horizontally to produce a wider picture when projected using specialised lenses. This was used for aesthetic reasons and promoted striking visual compositions.

Due to engineering implications when Television was being developed the screen size was limited to a certain size, which prompted the adoption of the 4:3 ratio (comparatively speaking: 12:9). So to view cinemascope movies there had to be a trade-off. This was originally to sacrifice much of the picture to view it as a 4:3 image. With the emergence of home video, bigger screen sizes and better image processing the trade-off became less severe, and 16:9 widescreen VHS video versions of popular films were released. This was met with a mixed response, and the ambiguous term 'full-screen' to describe the 4:3 version caused many people to stick to the traditional format, believing that widescreen version gave them less of the image. In reality the opposite is true. Even though the image occupies less of the screen on a traditional 4:3 TV set (with black bands filling the redundant space at the top and bottom of the screen), more of the original scene as the director saw it was in view. This type of widescreen is known as letterbox (as that is what it resembles!)

Incidentally, many films, especially those shown on TV a few years ago show the opening in 16:9 or 2.35:1 cinemascope letterbox format and then revert to 4:3 after the initial titles. This was simply because the names in the credits usually filled the whole screen in cinemascope and:

ECTOR
VEN SPIEL

doesn't mean as much as:

DIRECTOR

STEVEN SPIELBERG!

Widescreen televisions were slowly being developed. Once the technology to display an undistorted widescreen image was available, a broadcast format with the same capability was needed (the goal was originally to display a 15:9 picture with the HDTV (high definition TV) format, an analogue format using the same technology as the original BSB satellite signal. There were various limitations to this format and digital was starting to emerge as a superior medium). It may be surprising to note that widescreen display technology has been around for years-since the mid-1980s, but the time wasn't right to market it until there was an appropriate widescreen broadcast system to maximise widescreen's potential. Eventually a standard of 16:9 was settled upon to provide a good compromise between the original TV standard ratio (4:3) and the cinema widescreen format so both 4:3 television programmes and theatrically released films can be displayed with minimal distraction.

True widescreen broadcasts are not widely available on analogue terrestrial ** channels in the UK. Broadcast companies instead are investing in the digital service as this is regarded as the future of broadcasting and will eventually replace the analogue service. The 4:3 picture has been trimmed so it looks thinner on a widescreen TV set to encourage the viewer to accept widescreen.

DIGITAL TV

The potential for increased picture sharpness and audio clarity with the new digital service is excellent. However when companies surveyed what the average viewer on the street wanted from the digital service, they discovered that people ranked picture quality below the option of many specialised channels, interactive TV and TV-On-Demand. They also realised that the majority of average viewers would not really be able to tell the difference between the analogue and digital pictures.

With so many channels to transmit, the space for each channel is limited, which means that a type of compression has to be employed that is, a method of getting rid of redundant data to make the space needed to carry the TV programme smaller. This means that pictures up to the same standard as super-sharp DVD * pictures are out of the question for normal broadcasts.

The compression used often takes the form of not transmitting data that is repeated. For example, if there is a shot of a car travelling along a road and the camera is stationery, the background of the road will not change. In this instance the image of the road will be broadcast once, but the area where the car is moving will be transmitted every time there is a change. This reduces the bandwidth needed to send the programme to the viewer's home quite considerably. There is a slight limitation to this method however. Gone are the problems with ghosting and shadows on the screen, but as a result of compression there is the introduction of a less intrusive artefact, shimmer. This occurs in areas where there is fine detail, for instance on the grass of a football field. It is technically known as aliasing and filters are often employed to minimise this. It occurs very infrequently and does not detract from the action. The analogue image has been modified recently so the gap between analogue and digital pictures is closing. For technical details*

There are different methods of viewing digital television. It is worth considering this when buying a TV. Some TV sets have a digital tuner built-in. This will allow the viewer to receive the free-to-air * digital channels. On payment of a subscription to a company such as ON Digital which broadcasts digital TV through an aerial socket, additional digital channels are available through the TV aerial and the digital tuner. The channels that are available through this method are limited due to restricted bandwidth, but if it is your first foray into digital it does have a lot to offer. It is the only means of receiving digital TV without a set-top box.

The next system I shall mention is Cable TV. Companies such as NTL and TeleWest, offer this. Cable Television is not available everywhere, it is necessary to ring up the cable company in the area and check first. It involves connection to a cable running underground down the street. To receive cable television a modest installation fee is required and then a monthly subscription is charged for the television packages chosen. To make this option more economical the company will also offer their telephone service in with the package. Another way to keep the cost down is to see if the company will offer discounts for committing to their service for 12 months. Due to licensing and bandwidth restrictions the number of channels available is limited although there are more channels available with this method than digital TV through the aerial.

The last method is Satellite TV from a company such as Sky. There are less bandwidth restrictions with this method, so more packages are available to subscribe to. Although this can end up working out quite expensive, especially as the installation fee is higher than with the other options, and there is no telephone incentive package to soften the blow. Due to the technique used to broadcast satellite TV, it is necessary to have a dish installed on the outside of the house to receive the signal.

For sports fans the crucial thing to check is which company is showing your favourites!! The matches they have rights to do vary.

TYPES OF TV SET

There are various types of TV on the market. With the emergence of widescreen, traditional CRT (cathode ray tube) TV's-the type all of us have had in our homes since the dawn of TV, have become bulky. This has prompted television manufacturers to produce alternatives. Here is a brief overview with their relative merits and drawbacks:

TRADITIONAL CRT- the main attraction for purchasing one of these is the cost; they tend to be less pricey than the equivalent alternative, and within most people's reach. The disadvantage? Screen sizes are currently limited to around 36 inches in diagonal. They can be very bulky, especially in depth.

LCD- these give a bright punchy picture and can be completely flat, being just a couple of inches deep. The limitation of LCD is the technology involved limits the screen size, the biggest being 20 " or so.

GAS PLASMA screen- these start where LCD leaves off. The picture quality is indeed similar to LCD and is a technology that lends itself perfectly to larger screen sizes. The display area is not limited to the same extent as LCD or CRT-42" widescreen is the most desired size, and they can also be hung on the wall, which adds to their appeal as they don't take up much (if any) floor space. The major drawback is the hefty price tag: upwards of £4,000 sterling. The TV sets themselves don't contain a TV tuner so it would be necessary to consider the options to receive TV broadcasts. A set-top digital receiver could get around this constraint. There are also whizzy boxes available on the market that combine a computer, TV tuner, sound system and even make the tea (alright, that last one isn't true!), which can be bought as a package with a gas plasma TV screen.

REAR PROJECTION - these were one of the first types of widescreen television developed, and were once regarded as the dogs family jewels as they replicated the 'cinema experience'. This is very true in that screen sizes are very large, but as with CRT it causes the set to be rather bulky as the projection arrangement is housed inside. The major problems with this type of set, a drawback that is causing many people to think twice, is that it can only be viewed from face on. This is fine if you are in a position to design the living room around the TV and have your friends over in shifts to watch it. But at the risk of sounding biased, the disadvantages outweigh the benefits.

One last thing to mention: front projection. Not so much a TV set but a way of viewing television programmes. It requires a large enough living room, a tuner and a video projector. Definite pose-value though.

100 HZ-WHAT IS IT AND IS IT BETTER?

The answer to the second question first: yes and no. It depends where you're from. 100 Hz signifies 100 cycles a second, but this frequency doesn't mean much without knowing what it refers to. In brief: a TV signal is made up of several pictures shown in succession really fast, a bit like those cartoon flip books with a slightly different picture on each page. When the pages are flipped quickly it looks like a moving image. In its simplest terms: the frequency represents the amount of pictures (known as fields) displayed per second and is called the field rate. For technical information
*

In the UK the field rate is 50Hz or 50 fields (pictures) a second. This produces a discrepancy. The UK television system (PAL system I) is designed to be shown at 50Hz so to display it at 100Hz gives the effect of picture drag. Each field is effectively displayed twice. This can be very distracting. The system was originally developed to display the Japanese High Definition Television System (HDTV), which has a 100Hz field rate. For this application 100Hz is perfect. But when Japan's top-selling televisions reached the UK market they were sold with the awareness that they were superior in Japan, but often without the wisdom about the difference in broadcast system.

To the best of my knowledge there are no plans to alter the field rate of the UK TV signal. This means that the 100Hz televisions will not, at least in the foreseeable future, be compatible with the UK system PAL 625/50. There will be advocators of the 100Hz system in the UK, but to me it is like wearing Wellington boots to run a marathon. It will do the job but it is not what it is designed for.

WHAT ABOUT SURROUND SOUND?

Many televisions will come with a built-in Surround Sound option, many with speakers. If you are on a budget, it may be an option to consider. The televisions that come with this facility do not always provide value for money, or top quality sound. If possible, shop around for a separate amplifier that will often give a fuller sound and more functions. The picture quality should be the highest priority when purchasing a new television

I shall be adding to this section soon...

WHICH SIZE TELEVISION TO PURCHASE?

If you decide to settle for widescreen it will be necessary to have a little knowledge of which screen size will give a picture similar in dimensions to your current set. I shall be adding these details over the next couple of days. If you want to work it out for yourself, use trigonometry. Televisions are sold by their diagonal size eg 21".

To calculate the width (adjacent) and height (opposite) of a 4:3 TV:
opp = [insert diagonal size eg 21"] sine 36.86 degrees

adj = [insert daigonal size] cosine 36.86 degrees

To calculate the width (adjacent) and height (opposite) of a 16:9 TV:
opp = [insert diagonal size eg 24"] sine 29.35 degrees

adj = [insert daigonal size] cosine 29.35 degrees

POST SCRIPT: PAL system I specifies the type of PAL system in the UK. The word 'PAL' (short for Phase Alternate Line) describes the types of colour coding used. The 'system I' part describes the form of audio encoding used. The other PAL systems eg system M and N have the same scanning specifications as PAL I.

I am sure people will point out errors in my maths. Save your energy, I shall double check it before I add the screen size comparisons!!