Widescreen: 16:9 aspect ratio

4:3 aspect ratio

Unless you have upgraded to digital television in the last few years you will have noticed that your TV picture is now often a little smaller than it used to be, with narrow black areas at the top and bottom of the screen, as in the illustration left>

The reason is that the mainstream terrestrial broadcasters have now moved towards a widescreen future... Cynical observers might ask why? and point out that wider does not necessarily mean better, but the progress towards widescreen is now unstoppable.

However, the inevitable transition period is attracting criticism, especially from those who see their TV pictures getting smaller. This page is an attempt to explain, in easy terms, what is going on and what it means...

The 14:9 compromise: most widescreen programmes are now shown like this on analogue services and other non-widescreen services such as UK Gold.

The introduction of widescreen pictures to UK television has done more to confuse viewers and polarise opinion than any other innovation in the medium's history. Not that there have been that many innovations when you come to look at it:

• Higher definition 625 lines
• Programmes in colour
• Teletext
• NICAM digital stereo sound
• Satellite broadcasting
• Digital transmission
• Widescreen

Higher definition - 625 line - television (and with it a new network,  BBC2), colour television, teletext and stereo sound were all hailed, universally, as welcome innovations. Satellite broadcasting was a great feat of engineering but it can't really be said to have been a technical innovation, it simply offered more of the same!

Digital transmission and the widescreen format it allows have been the first real innovations since then but are their benefits quite so evident?

Note: TRADITIONAL ANALOGUE TERRESTRIAL TRANSMISSIONS ARE NOT WIDESCREEN. In fact, viewers of traditional analogue services are seeing smaller pictures, and widescreen sets can often be seen displaying mis-shapen pictures, so what's going on...

There will always be a problem when trying to view a widescreen picture on a standard 4:3 set - see panel, right >

WHAT IS WIDESCREEN?
Widescreen is television's ability to transmit pictures which are wider than those we have traditionally watched since television was first invented.

In the past television has sometimes transmitted feature widescreen cinema films by leaving black bars at the top and bottom of the screen where the screen is blank, but this is rarely popular with viewers because although it allows more of the film to be seen it produces a smaller picture for the viewer and is more like 'shortscreen' than widescreen. 

True widescreen tv uses all of the transmitted picture area and is intended for viewers who have widescreen tv sets but, crucially, the set-top box decoders allow viewers with traditional 4:3 sets to choose between two ways of showing the widescreen picture on their sets. They can see widescreen programmes letterboxed, with black bars top and bottom, or they can fill their screen by 'zooming' in to the centre of the widescreen picture (this is known as 'centre cut-out').

The transmission and recording video format
is known as 'full-height anamorphic'

Unfortunately, the retail industry, with much to gain from selling new widescreen sets, has done much to confuse the public about the advantages of widescreen, with shop after shop displaying sets showing conventional, non-widescreen pictures

s t r e t c h e d

to fill the new shape screen. But that is not what widescreen is about and there is no excuse for it.

Doing the job properly and showing good quality widescreen pictures requires either some esoteric video distribution equipment or a separate set-top box or DVD player for each set, so very few shops manage to do this properly. This will probably only change when every set is an IDTV (integrated digital tv) with its own decoder built-in.

A standard 4:3 picture stretched into widescreen

WHY WIDESCREEN?
The whole idea of widescreen is based on the concept that a wider picture is actually more pleasant, more aesthetically pleasing to watch, though it would be naive to suggest anything other than the fact that television manufacturers want to use it sell us is a home viewing experience one step closer to the cinema experience.

The first 'home cinema' systems brought Dolby Surround sound and larger screens to the film and hi-fi enthusiast, with Laserdisc offering better picture and sound quality. With all this going on television was in danger of being left behind, but with digital and widescreen it has now caught up, offering picture quality similar to DVD.

Some sceptics still fail to see the point of widescreen, arguing that it is of no benefit to some types of programme but ultimately there is no denying that 16:9 is a more pleasing shape and that there is no programme which fails to benefit from being viewed on a larger screen. And that is the key - a larger set is required otherwise you inevitably find yourself watching a smaller picture.

WHAT WIDESCREEN?
Any aspect ratio could have been chosen for widescreen tv, so how and why was the current standard derived?

Apart from being a good, mathematically convenient compromise it is also close to the classically accepted golden section or golden ratio admired by artists, architects, scholars and mathematicians.

1. The degree to which allowance is made for viewers watching on traditional 4:3 sets, particularly while they remain the majority
2. How you mix widescreen and non-widescreen material within individual programmes.

The first of these situations can be seen as temporary, but it is no less tricky for that. The option favoured by the UK broadcasters is to transmit most widescreen programmes on analogue at a compromise aspect ratio of 14:9 (1.56:1). This produces a picture which is slightly letterboxed and loses a little of the extreme left and right.

A 16:9 picture reduced in size for transmission in 4:3 format. Note the black bands at the top and bottom and the areas of the picture lost at the sides. The aspect ratio of the visible picture is 14:9

You might think that the solution was obvious, and that 4:3 material should simply be transmitted as it was made, as a 4:3 picture within the 16:9 frame - and at present that is the practice adopted by BBC Sport -  but some broadcasters see two problems with this.

1. Viewers are thought not to like the wide vertical black bars which result from 'pillarboxing' because they are unfamiliar with them
    
2. Although pillarboxing does (or could) work well for digital viewers there is another problem is the programme is then resized with an Aspect Ratio Convertor and broadcast to viewers of an analogue transmission at 14:9. That problem is that the 4:3 picture is then surrounded by black bars and the picture is said to 'float'.

Personally I dislike the use of the 14:9 aspect ratio for analogue transmissions as I believe it is a compromise which is very unsatisfying from the viewers' perspective. See my no compromise article on the Transdiffusion site for more about this.

This demonstrates the potential problem
 of the 'floating' 4:3 picture

A 4:3 picture zoomed and cropped to 14:9 - everyone sees the same thing, but note that the top and bottom of the picture is now missing.

SCREEN SIZES
One important thing to remember, if you're getting irritated by your smaller TV picture is that paradoxically you are actually seeing more of the original widescreen picture but to take full advantage of widescreen you do of course need a widescreen tv!

Traditionally the size of a tv screen has always been defined by measuring the diagonal, and this tradition looks likely to continue. Unfortunately it makes comparisons between 'ordinary' sets and widescreen sets very difficult. In a true comparison the height of the picture should be the defining measurement as shown by the examples in the table on the right.

LINKS TO RELATED SITES
BBC Reception
Andrew Wiseman's Digital TV - Beyond the Hype
The SCART connector