And yet, Richie has also always been a man of few words. How hard was it to persuade him to talk?

wine industry, it was cancelled in case it gave the impression New Zealand was populated only by ‘‘drunks and Dalmatians’’.

Holidaying in Opononi with first wife Gillian, Shadbolt swam with Opo just when the cheeky dolphin was winning fame. Returning to Wellington, he was told to ‘‘find a cameraman and get back there fast’’. He reimagined the Opo story later in his 1969 novel, This Summer’s Dolphin.

Wellington-based researcher Clive Sowry was the Film Unit archivist in Avalon from 1974 to 1987, and has an encyclopedic knowledge about its role.

‘‘The National Film Unit really helped nurture the film industry we have today,’’ he says, ‘‘while the lab, along with processing films, played a part in supporting an emerging private film industry in NZ, and in the preservation copying work that has saved so much of NZ’s film history.’’

While it is difficult to know how much was actually produced in its five decades (the last film was made before it was privatised), Sowry estimates about 1500 films were delivered.

‘‘They were really a great treasure, showing the way we were and the way we saw ourselves. In the 1940s in particular, it was about seeing New Zealand in a positive light as New Zealanders, not as a brighter Britain. The films weren’t about Hollywood or America either, but always with the idea, ‘Why shouldn’t New Zealanders be up on our screens too?’ ’’ I didn’t realise how much attention was on him until we started to make this, and then I started to go ‘‘oh, my gosh, he’s in the paper nearly every day’’. Then, when we were filming with him, there were a huge amount of people around him all the time.

There’s a scene in the film when he’s flying and a fellow pilot comes out for a selfie, followed by another one who worked for Emirates – he wasn’t even a Kiwi. Just before that, we’d filmed footage of him walking through the airport. Everybody was stopping him, in the lounge and as he boarded – I wouldn’t have the patience for that, honestly. He’s pretty media savvy. He knew that if this was going to be a film, it had to be more than just what you might deliver for a Sky Sports interview. He was really interested in telling his story because it was coming to an end.

Did you have any cinematic inspiration for the tone or style of story you wanted to tell?

Strangely, the In Bed With Madonna documentary that came out in the 1990s, in the sense that here is a film largely told by the character, that in some ways is a celebration, but is also not sycophantic and feels like a film.

That, to me, was the most important thing. More recent documentaries like Amy and Senna were touchstones, but in the end, it was almost a mash-up. People always want to know that it’s going to be ‘‘this mixed with this’’, but we wanted it to feel original.

Was there ever a time when you worried that you might not get the fairytale ending?

We were thinking about that from the moment we started making the film. Richie put it on the line right at the start, when he said that after his last game he was going to be really happy or extremely disappointed – there would be no inbetween. If they’d lost, maybe we might have needed to film for a bit longer. We’d worked out that the French rematch would probably happen in the quarterfinals and losing there would have been dramatic, but still quite a big storypoint.

Our fear was if they lost to South Africa in the semifinals, which was kind of a real ‘‘in-between’’ thing, not getting to the final. That was an incredibly tense watch. I was thinking ‘‘my god, this is not fun’’.

To win that game was a relief, after that I was pretty confident they could win the final.

And that’s when your toughest work really began? Editing all that footage into a coherent and entertaining documentary?

It was a little overwhelming actually. It was like a year’s worth of observational documentary. The day after they won the World Cup, I sat in my office with a handful of drives with all this footage that we shot, and then came the torrent of archival stuff – you think he played 148 games just for the All Blacks and every game is 80 minutes long. Then you start going through the news archives and asking broadcasters ‘‘what have you got’’, and you get these screeds of paper with abstract descriptions. In the end, we had around 700 hours in the edit suite that we’ve edited down to 105 of the finest minutes.

How much of that footage came from the McCaw family archive?

Definitely more than 20 hours. Every now and then we’d discover that his mum and dad had taped over things. We’d find a family moment interrupted by a ‘‘farming special’’. You know, in those days VHS tape was precious and people used to use whatever tape was most handy at the time.

So, finally, have any of the family or Richie seen the finished film yet?

Tuesday’s premiere at The Civic will be the first time any of them have seen it in its completed form, with the mix complete, the colourgraded, and all the graphics included. I think it will be nice for all of us to see it in that environment with the public there as well.

Tickets are still available for the world premiere of Chasing Great at Auckland’s Civic Theatre on August 30. See ticketmaster.co.nz for more details. The film opens nationwide on Thursday.