Film-makers won the approval of the family of the late Dougals Adams with their movie of his cult novel, The Hitchhikers' Guide To the Galaxy, but pleasing all the fans has proved to be more difficult. Steve Pratt reports.

Plans to bring The Hitchhiker's Guide To The Galaxy to the big screen very nearly ended with the death of its creator Douglas Adams. When the writer died five years ago - of a heart attack at the age of 49 - the long-mooted, much-delayed movie version looked like it would never happen.

Film-makers on both sides of the Atlantic grappled with the problems of translating the intergalactic adventures of Arthur Dent, Ford Prefect and Zaphod Beeblebrox into a cinema film, a process that Adams himself had been working on for some time.

Executive producer Robbie Stamp was adamant that the movie of the radio series, TV programme, books and computer game should only be made with the approval of Adams's family. The fact that this week, 25 years after the original radio series began, the movie finally opens is as much down to them as the makers.

"I talked with his family as to whether they wanted us, if we possibly could make the movie happen," explains Stamp, who was chief executive of h2g2, a company he founded with Adams which was involved in computer games, TV, mobile Internet distribution and e-commerce deals.

"They felt very strongly because Douglas had so desperately wanted there to be a movie, that it would be a vindication of everything he believed in if we could make a great movie."

Eventually, he recruited director Garth Jennings and producer Nick Goldsmith, whose UK production company Hammer and Tongs have been behind music videos and commercials involving Blur, REM, Supergrass and Pulp among others.

'They worked on a boat on a canal which, ironically, was just ten minutes from where Douglas used to live. We started a relationship over tea and chocolate biscuits, which is a very good English way to start a relationship, and just took it from there. I really knew the movie finally had found the people who, after 25 years, were going to bring it home," says Stamp.

The Hitchhiker's Guide finds earthman Arthur Dent having a very bad day. His home faces being bulldozed, he discovers his best friend Ford Prefect is an alien, and that the Planet Earth is about to be demolished to make way for a hyperspace bypass. Hitching a ride on a passing spacecraft is his only option and one that leads to him finding out just how useful a towel can be and the meaning of life.

The Office's Martin Freeman heads the cast, with Stephen Fry as the book, Alan Rickman voicing Marvin the paranoid android and a trio of US actors: Mos Def, Sam Rockwell and Zooey Deschanel in other roles.

Bringing a cult favourite to the screen was never going to please everyone. Fans are notoriously obsessive about changes to something they know and love. Stamp says he felt a real responsibility to Adams and his family, as well as his fans.

One of the most crucial moments was showing the film to Adams's family, several of whom have cameo roles in the film. "They all loved it, they genuinely loved it," he reports.

"Had they not been able to look us in the eye, that would have been an awful moment. I was very keen that they should be involved, that they should be comfortable and happy with what we were doing.

"The decision to go ahead was basically entirely based on discussions with them. Had they said they didn't want it to happen, it wouldn't have happened. But they're delighted. Having his ten-year-old daughter Polly say, 'it's cool', that's great to me."

He points out that the film isn't a literal adaptation of the novel, just as the radio series wasn't a literal adaptation and neither was the TV series or the computer game. "There's no single definitive Hitchhiker's Guide story, and never has been," he explains.

"The book, radio, TV, computer game all share some characters and plot elements but they add, remove, change or re-order others. Douglas's various script drafts did the same."

Hammer and Tongs weren't sure about taking on the project at first. "Initially, when we read the script all these memories came flooding back of this thing that we'd grown up with and loved so much," says Jennings.

"The second reaction was that we couldn't do this because there were loads of people like us who were fans, who take it incredibly seriously and that's too daunting a task.

"Then, when you start to wonder how you would design Marvin, or how you would do a Vogon poetry scene, you suddenly realise it's the best job in the whole world and you can't resist it."

One fan - Adams's unofficial biographer M J Simpson - did pounce. In a 10,000 word website review he described the film as "staggeringly, jaw-droppingly bad". That was one of his kinder comments.

Stamp knows the view isn't shared by other Hitchhiker's Guide followers.

"If it represented all the other fan voices out there, the other equally respected and respectable fans, I'd probably be looking for a very isolated cabin in western Alaska with no Internet access. But it isn't. You only need to go out there and see dozens of other terrific fan reviews," he says.

"I know that non-fan response would have been just as important to Douglas. We always knew we needed to bring the vast majority of fans with us. You only need to look at the other reviews that are out there to see that we're doing that."

Jennings recalls a US test screening in Pasadena, turning up at a cinema in a mall to see people queuing round the block. "It was revealed afterwards that only half of the audience had heard of the book. The other half had just come along to this weird-sounding movie," he says.

"The first five minutes were terrifying. I hadn't finished the film, so I was seeing which bits worked and which bits didn't. It turned into the best evening ever, where two years work worked. The fact that it worked across the board was really satisfying."

The film-makers didn't want to overwhelm the script with computer-generated effects as many of today's blockbusters do. "It would have been such a shame to try and outdo The Matrix or something like that. We wanted to do it in a more inventive way - more old Star Wars than new Star Wars," he says.

"To have real creatures and still use CG elements but not have them dominate because it's a comedy first and foremost. Even my mum is so used to those effects now that she's not impressed. We shouldn't try to do that.

"I can honestly say that even if we'd had double the budget our approach to the film would have been the same. It needed to be done in that way, so instead of all the usual things you're used to seeing in sci-fi and adventure movies, like a spaceship crashing, you end up seeing it from a crab's point of view.

"Douglas was good at focusing on all the little details that lead to a bigger picture. We tried to take that approach throughout the movie."

They followed the Hitchhiker's Guide order DON'T PANIC! when it came to filming. "We spent a good nine months revising for this project before we got the go-ahead," says Goldsmith.

"Garth had done storyboards for most of the film. We were very, very well prepared. This was our first film so we did over-revise. On the whole, pretty much all the way through, panic didn't set it."

Jennings adds: "Generally, it was all the usual stuff about the weather being crap that was annoying. We really overdid it a bit in the planning stage. When we came to shoot, it was quite straightforward."

* The Hitchhiker's Guide To The Galaxy (PG) opens in cinemas on Thursday.