Media: It's big, expensive and coming soon to a cinema near you

Imax, the biggest of big-screen cinema formats, is about to arrive in Britain's museums and municipalities. Paul McCann asks why so many are planned and whether they are simply a lottery-funded gimmick or the cutting edge of entertainment.

After years as a rather hokey novelty for parents to take their children to on wet Yorkshire afternoons, Britain has gone mad for the Imax cinema screen. Until now there has been only one of the huge-format screens in the country, but there are plans to open 10 in the next three years.

This week, builders moved on to a site in the middle of a roundabout at Waterloo, in south London, where they will construct Europe's largest cinema screen, a seven-storey Imax for the British Film Institute. And next month, the Trocadero centre, in central London, will open its new Imax - the first since the Museum of Film and Photography in Bradford opened its screen, 14 years ago.

But London's Imax mania does not stop there. The Science Museum is to build an Imax that will open in 2000 as part of its Wellcome Wing, and Warner Brothers plans an Imax as part of its multi-screen development inside the former Battersea power station.

Outside London, the trend for big screens is spreading like a rash. Bristol, Bournemouth, Birmingham, Belfast, Manchester and Dublin will all have Imax screens by the millennium.

This is a remarkable turnaround for a film format which is 25 years old and has never really taken off in Hollywood. The technology is based on a film frame that is 10 times bigger than a conventional 35mm frame. This gives images a much higher resolution and allows the film to be shown on screens so big that they spread outside the audience's field of vision.

"There has been a complete dearth of screens and now there is an explosion," says a delighted Alison Roden of Euromax, the format's trade body. "It is being driven by two things. In America there has been a surge of interest as multiplex cinema operators try to give themselves a unique selling point. They can either have better popcorn, or they can have an Imax.

"And then the National Lottery has had a huge part to play, because of the amount of money earmarked for capital projects."

But the suspicion shared by some that Imax screens are the ice-skating rinks and ten-pin bowling alleys of the Nineties: unimaginative municipal regeneration schemes that are destined to be white elephants. Ms Roden, naturally, disagrees: "The growth is not coming from institutions but from commercial companies. More films are being made every year and people are making money from Imax films."