First time in 4K: Diana kiss that made nation stand still

But the TV technology of the time could not capture the intimacy of the moment. Blown up on today’s big screens, the royal couple are indistinct, the faces in the crowd a blur.

Now, 36 years after the wedding that made the nation stand still, and a week before the 20th anniversary of Diana’s death, a newly restored version of a little-seen film shows the event in a clarity not previously possible.

The footage, the only cinema-quality film record of the day, has been digitally enhanced and released to YouTube in 21st century ultra high definition.

It has been pulled from the archive of British Movietone, which was allowed to film the wedding on 35mm film, a format capable of being enlarged to today’s 4K resolution.

“It is simply stunning and a world away from the 1980s videotape versions we’re familiar with,” said Alwyn Lindsey of the Associated Press, which acquired the archive last year.

Jenny Hammerton, who led the restoration process, added: “All the details you couldn’t see before, now show up perfectly.

“The faces in the crowd on the long shots looked like pink blobs. Now, if you were there, you can probably pick yourself out.”

The new version, created from the lustrous original colour negative film, includes the ceremony at St Paul’s Cathedral, as well as the procession and the crowds beneath the Palace balcony.

Peter Hampton, a former executive producer at Movie­tone, who was also involved with filming the weddings of Princess Margaret and Princess Anne, said: “This was going to be the wedding of a king, so it was really, really important at the time. It was also at a time when film was dying out and video was coming in, so we had all the logistics of moving all the heavy cameras.”

He said that unlike video units, the film cameras could shoot for only 10 minutes at a time before they needed to be reloaded.

“All the shots had to be carefully timed before we could film them so we didn’t miss out someone saying, I do,” he said.

Ms Hammerton added: “It is footage that was shot on the greatest format ever invented. There is so much detail.”

Andrew O’Hagan, one of the technicians who digitised the film, said: “It’s like a little glimpse into the past without the veil of the poor technology of the time that was limiting it.”

The original TV coverage of Charles and Diana’s wedding on July 29, 1981, was seen by an estimated global audience of 750m, which made it the most popular programme ever broadcast. In Britain, a national holiday marked the occasion.

But after the couple divorced in 1996, the Princess described the day as “emotionally confusing”.

Her biographer, Andrew Morton, said: “Diana told me initially that it was the worst day of her life because she just felt like, as she said, a sacrificial lamb.”

The original purpose of the wedding film is lost in time. Movie­tone had ceased production of its cinema news­reels by 1981, and was shooting just occasional documentaries and corporate films.

“We would love to know more about the film’s history and production,” said Ms Hammerton. “There must have been about a dozen cameras on the day, but the paperwork wasn’t kept. It’s possible the film may have been shown overseas.”