SkyDigital and ONdigital compete for market

by John Henshall



A wide-screen (16 x 9 aspect ratio) picture


Television has been the catalyst for many developments in digital still photography. The first big use of the CCD, the solid state image sensor which converts light into electricity, was as a replacement for the large thermionic tubes used in early television cameras. CCDs are now used in almost every digital still camera and desktop scanner. Television also spawned the first filmless stills camera, the Sony Mavica, from which the digital photography market developed.

When I started work at the BBC in the early 'sixties, television hadn't changed much since itJohn Henshall/CPS EMItron began in the 'thirties. Pictures were made up of 405 lines, there was no colour, no Nicam stereo, no domestic video tape recorders, no satellite transmission. Yet the power of television had already managed to reduce 'going to the pictures' to a point where cinemas were becoming bingo halls and furniture stores.

RIGHT: The young John Henshall operating his earliest electronic camera - a CPS (Cathode Potential Stabilised) EMItron - at the BBC, 1962.

On the bus home from the studios in Shepherds Bush, the flickering blue light on the curtains of the houses I passed told me that the occupants were watching television. Audience research said that just under half would be watching the channel for which I worked. It was a warm feeling.

Seven years earlier, before 'commercial' television came along, everyone would have been watching BBC. That would have been an even warmer feeling. Television has only one audience, and each member of that audience can watch only one thing at a time, no matter how many channels we give them. In 1964 BBC2 split the audience three ways. Channel Four, the many channels of satellite television and video cassette rentals each further subdivided the audience. More channels means more choice and more competition but either the audience has to pay more or programme budgets and quality drop. In the early 'sixties the size of the television audience was increasing. Today, it is shrinking. What would the audience be watching if I made that bus journey today?

Against that background, television is now undergoing its most radical change ever: it is going digital.

'Coming digital' might be a better way of putting it. Like most things, television has been influenced greatly by the digital revolution over the past few years. Cameras, recording and editing are already digital. These are relatively easy, for the broadcasters have total control over the equipment they use. On the other hand, they have little or no control over the equipment you use to receive and decode their transmissions and this is precisely where the big change must be: digital delivery is coming to a lounge near you.

It hasn't been an easy problem to solve. Although each frame of television is quite low resolution compared with other digital images, the problem is that there are twenty five frames every second. One frame is roughly a megabyte, so that adds up to about twenty five megabytes a second -- a lot of data to deliver to your home constantly without any interruptions. So the data is compressed, which also enables more than one programme to be broadcast simultaneously in the bandwidth previously taken up by just one.

Once upon a time the BBC designed and installed its own transmitters. Holme Moss, the BBC's third television transmitter after London and Birmingham, was built in the early 'fifties high on the Pennines between Manchester and Leeds. Its output covered from the East coast of England right across the West coast and on across the Irish Sea to the Isle of Man and Ireland; to North Wales; to the Lake District; to a prospective audience of eighteen million people -- more than any other television transmitter in the world. Today, the BBC has no transmitters. This part of its service has been privatised.

So the BBC now has to rely on others to transmit its programmes. In the case of digital, that means BSkyB or a consortium of Granada and Carlton -- the BBC's arch rivals in the fight for audience share. Ultimately it comes down to politics, money and power -- now the driving force behind television and all other publishing.

You could not fail to miss the hype surrounding the launch of Sky's satellite digital services on 1 October 1998. The Sunday papers were full of supplements telling us how great the new SkyDigital service would be. "It's what your television's been crying out for," "Technical excellence," "A choice of up to five films an hour," "Up to two hundred channels." All this for just £199.99 for a dish and set-top box? No, there's also a 'digital connection fee' of £30. That brings us BBC1, BBC2, two other BBC channels (BBC Choice and BBC News) -- already covered by our license fee -- plus Channels 4 and 5. After those, all other channels require additional subscriptions. Sky's "value pack" brings five channels: Sky One, Sky News, Discovery Home & Leisure, Bloomberg and QVC for £83.88 per annum (the minimum subscription period to SkyDigital). That's only £7.62 short of the £91.50 BBC license fee. Sky's "family pack" of channels costs £143.88 per annum -- £52.38 more than your BBC licence -- and that still doesn't include "premium channels" such as movies and sport, for which prices are "available on request". And the dedicated MUTV (Murdoch United TeleVision?) channel costs another £59.95 per annum.

More choice certainly does mean a lot more money, especially as you can still only watch one thing at a time. Sky's subscription rates are so high that I suggest you buy two BBC licenses instead. It is better value and, of course, 'it's [still] your BBC' -- at least until the terrestrial analogue transmitters close down in a few years time. Then you'll have no choice but to pay Rupert Murdoch. Or ON digital.

ONdigital (formerly known as British Digital Broadcasting) are scheduled to begin digital terrestrial broadcasting on 15 November 1998. Signals will be received via a normal television aerial but you need a(nother) special box to decode the signals for viewing on your existing television set. The digital channels are transmitted alongside the existing analogue channels but only need around a hundredth of the transmitter power. ONdigital can carry up to thirty channels -- not so much 'choice' as SkyDigital but still twenty nine more than you or I can watch at the same time. And ONdigital will also carry BBC, C4, C5 -- and ITV, which is missing from Sky.

Another player in digital delivery will be the cable companies, which might in time become the best method. As television and the Internet come together, a good fibre cable system could deliver plenty of bandwidth for both.

One of the disadvantages of being an early adopter of digital television today is that you will need a set top box for each analogue television or video recorder in your household. That's expensive. In time, all televisions receivers will be digital.

There is a lot of hype about how much better the quality of digital television will be. Terrestrial channels have enjoyed good (Nicam) stereo for years but digital stereo will certainly be a big improvement for Sky, compared with its present low-quality analogue stereo. Terrestrial digital will not suffer from the common terrestrial analogue problems such as 'ghosting' (delayed reflections of the signal from large objects) and 'snow' (weak signal). But if you already have a good aerial and receiver, I doubt you will notice much improvement. In fact you might see some degradation in your analogue pictures, due to digital transmitters in neighbouring areas using the same channel.

Coincidental with the coming of digital will be the gradual move to widescreen (16 x 9 aspect ratio) television receivers. It's interesting to note that widescreen was invented by Hollywood in a vain attempt to check the advance of television. Though it does present some problems, especially in the display of older (4 x 3) format programmes, with suitable material -- such as feature films -- the impact is stunning.

It's a good time to 'turn on' and 'tune in' to developments and opportunities in television. The 'drop out' part may come when Sky fights it out with ONdigital.

Let battle commence.

As seen on TV ...

This is how Burford High Street, in Oxfordshire, would look on a conventional 4 x 3 aspect ratio television set.
A 16 x 9 set displays a wider image which gives a much more impressive sense of space ...

... especially suitable for light entertainment spectaculars ...

... but not so good for portraits, where we have to crop into the face to fill the screen. This emphasises the "landscape only" limitation which film and television has always suffered.

Early Limitations

Early 405-line pictures suffered from poor geometry and limited resolution as the above frame of telerecording shows. Compare this with an original 2 x 2 inch photographic transparency of Test Card "C" (below). Both are 4 x 3 (1.33 to 1) aspect ratio.

Widescreen format 16 x 9 (1.78 to 1) will gradually become the norm in the future of digital television, though this will present problems for the display of 4 x 3 material.
Filling the height of the screen to avoid cut-off results in black bars each side of the image.
Filling the width of the screen without distorting the picture results in the loss of the top and bottom portions of the image.
Stretching the picture to fill the wider screen results in distortion which makes subjects shorter and fatter.

Useful contacts

BBC Digital



This article first appeared as "John Henshall's Chip Shop" in "The Photographer" magazine, November 1998.
This document is Copyright © 1998 John Henshall. All rights reserved.
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