The premiere league

But as the massive publicity machine to promote the year's most eagerly-awaited film ground into motion, there was the man who started it all in a shed at the bottom of his garden attending an altogether different first showing.

Like The Golden Compass, this film also featured talented young actors. But it was hardly a multi-million-pound affair. In fact, the whole thing lasted for little more than ten minutes, having been made by youngsters from the Pegasus Theatre, Oxford, to highlight their work.

The former Oxford teacher, whose novels are set to inspire one of the most costly film franchises of all time, clearly felt among friends as he prepared for the blockbuster release that will surely send Pullman's fame into a different universe.

Yet his appearance at the fundraising event for the Pegasus and his ease with the young children, also gave the clearest indication that The Golden Compass is unlikely to set him too far off course. Pullman simply has too much respect for his readers, his books and Lyra Belacqua, the central character of the His Dark Materials trilogy, to depart from the path he has charted for himself.

His reflections on education, youth theatre and religious tolerance as he answered questions offered the surest proof that his own moral compass is safe and secure.

He arrived at the Pegasus event, held at St John's College, having flown back from America where he had finally seen the final version of the film, starring Nicole Kidman and Daniel Craig.

We will never know what J.R.R. Tolkien thought of the Oscar-winning adaptations of The Lord of the Rings trilogy.

But, happily, Pullman can tell us precisely what he thinks of the movie version of his book Northern Lights.

The good news for His Dark Materials devotees, and no doubt those who spent $180m making the film, is that he likes it a great deal.

"I saw the final cut of the film last week and I'm pleased to tell you that it's terrific," he said speaking at St John's. "I always knew that it would look wonderful because of the great designers and costumes. I also knew the performers would be right, having such a great cast."

But there had remained things that he could not be totally sure of until "the last minute", when the final, edited version was ready. Now all lingering uncertainties appear to have vanished.

"It works very well. The story moves quickly. They tell my story without deviation, repetition or hesitation," recognising that he was among fellow fans of Radio 4's Just A Minute.

He recognises too the level of expectation as millions await their first glimpse of his strange world, where witches rule the northern skies and a body known as the Magisterium seeks to control all humanity.

"More people will see the film in the first week than have ever read one of my books, or even heard of them. If it is a good film, which it is, it will encourage people to read the books."

Like The Lord of the Rings, The Lion, the Witch and the Wardrobe and Shadowlands before it, the film will certainly draw thousands of visitors to Oxford, where the story begins and ends.

For the Oxford in this alternative universe is still wonderfully familiar, featuring the Covered Market, Jericho's narrowboats and Pullman's alma mater Exeter College (the model for the fictional Jordan College).

"It had to be Oxford, though not quite the Oxford we know," Pullman told one young questioner. "Oxford is a very mysterious place. Those who live in Oxford sometimes forget that. Many writers of children's books past and present have chosen to come to Oxford. Perhaps Oxford chose them."

While the city can only delight that he has given another layer of greatness to this tradition, the film's director Chris Weitz insists Pullman's books could not be more different to Narnia or The Lord of the Rings.

Weitz said: "Philip Pullman's vision is unique. The main challenge was to imbue his humanity and spirit into these special effects. We're not trying to wow people with the biggest explosions or try to create 15,000 Orcs.

"Take the daemons. It's very important in the film that these creatures represent each person's soul, and are acted in concert with what our human actors are doing."

Then there are entire armoured bear-on-armoured bear battles to worry about.

The merchandising opportunities over Christmas will be massive, with tie-in books, movie replicas, games and no doubt flesh coloured Lyra dolls that glow in the dark.

But there are also millions of readers who cherish every word of this complicated, multi-layered cosmic quest to be considered.

The author said: "I hope people who have read the book will feel the film is true to it. I think they will. They are faithful to the story.

"We all know that when we see the film of a book we have enjoyed, we say, 'she never looked like that. They have changed the ending'.

"The biggest problem is that they are not the faces you saw in your head when reading the book. If you see the film first, then you can never forget the faces of the actors. But in this case I don't mind because the actors are so good."

Pullman is full of praise for Kidman's "amazing versatility" and ability to be seductive and terrifying at the same time. The actress recently revealed that she received "a gorgeous letter" from the author after she had initially expressed doubts about taking on the role of Mrs Coulter.

But the really crucial thing for him was finding the right girl to play Lyra, the 12-year-old ward of an Oxford college, who is flung into an adventure that takes her to the wilds of the icy north, where she gains a powerful ally in a great armoured bear.

While Pullman says his involvement in the film was slight, he took a close interest in how the quest for Lyra was going, repeatedly calling on the film's producer, Deborah Forte, to monitor progress. When he was sent a DVD of 40 girls in the running, he immediately judged that "it was down to two". One of the pair he identified was Dakota Blue Richards, from Sussex, who was eventually chosen from 10,000 girls for the part.

Pullman has always maintained his skills as a storyteller were developed while working at Marston Middle School. He had not enjoyed studying English at Oxford University as much as he had hoped because he was not taught what he most wanted to learn - how to write.

After taking his last exam, he knew exactly what he was going to do.

He would recall: "I was going to begin a novel on the morning after the last of my final examinations and finish it a month or so later. It was going to be published before the end of the year and the film rights sold for a million pounds. And I'd be famous and rich."

Things certainly did not go as planned. For he first worked in a Moss Bros store in London, went into teaching and slowly learnt his craft.

Recounting legends from Homer's Illiad over and over to 12-year-olds, he says, provided the best apprenticeship for him as a story teller.

Pullman, who later taught at Westminster College, continues to hold strong views about the best way to inspire young minds.

"I worry that at schools in daily lessons, children do not have the space and time to get involved in creative things. I am a great believer in fun and pleasure.

"You hear politicians talking about 'basics' in education. By 'basics' they mean spelling and grammar. But they're not basics because, as those who use a computer know, they can be corrected at the last minute. What is basic is developing a confidence and delight in language."

He was asked too about his views on religion, as he had been at the Oxford Literary Festival in the summer. On that occasion, he had rejected the suggestion that the film had an anti-religion theme. "Not anti-religion but anti-oppression and anti-authoritarian," he insisted. "It's opposed to the use of theocracy for political gain. The church in Lyra's world is very different from our own."

You sense he has little relish for many more questions about dramatising the death of God and the influence of Blake and Milton.

Over the last three years he has been working on a rocking horse for his grandchildren, which is now completed, and taken up the electric guitar again.

But with his fan base soon to swell by millions more, he most of all wants to get back to his writing.

He is in the middle of another novel about Lyra, The Book of Dust, which will take another year to finish.

Once the film is out, he is proposing to disconnect his email, take the phone off the hook and pick up his pen.

"It will happen. I have to psychologically because if I didn't I would go mad."