Fiona Adams, a photographer who captured a memorable image of the Beatles, jumping in the air, just as the band was gaining worldwide fame, died June 26 at a hospice on the British island of Guernsey. She was 84.

Her family announced her death in a notice in the Guernsey Press newspaper. The cause was not disclosed.

After working in London in the 1950s, Ms. Adams spent two years in Australia before returning in 1962 to a London that seemed transformed.

“I was walking around in a different world from the one I’d left a few years earlier,” she later said. “Here I was in an exciting new environment with new, fun clothes and a new music scene.”

At the time, the Beatles were just becoming established in their native country after honing their act for two years in Hamburg. The band developed a strong following and changed its look, adopting the soft, forward-brushed “moptop” hairstyles suggested by photographer Astrid Kirchherr, who died in May.

By 1963, when Ms. Adams met the Beatles at a London studio, they were on the cusp of international stardom. She was working for Boyfriend magazine, which catered to teenage girls — who were the core of the band’s fan base.

“I just sat down next to them and said I was from Boyfriend magazine and would they mind coming up to the studio for a shoot the following week, and they said fine,” she told the British website Culturevoyage in 2008. “It was as casual as that in those days. You didn’t have to go through a manager or any other official channel.”

Ms. Adams, who preferred shooting outdoors, often scouted her locations by riding around London on buses. For the Beatles, she found a bombed-out building from World World War II that offered interesting photographic angles.

She lugged her equipment down into the crater, as the four Beatles cavorted above her. Recalling the portrait photography of Philippe Halsman, who often had his subjects jump as he snapped the shutter, Ms. Adams asked the Beatles to do the same.

“The boys did their bit and stood patiently — beautifully silhouetted against the sky and the buildings,” she recalled, according to the Guardian newspaper. “I set up my camera and shouted: ‘One, two, three — jump!’And they jumped — twice. Cuban heels and all.”

Her most memorable image captured the Beatles seemingly about to tumble off a cliff — or soar into the heavens. The photo created an immediate sensation, embodying the group’s iconoclasm and insouciance in a single image.

The Beatles used it for the cover of a British-released extended play record, “Twist and Shout.” When it was displayed more than 40 years later at an exhibition of Ms. Adams’s photography at London’s National Portrait Gallery, the curator, Terence Pepper, called it “one of the defining images of 20th-century culture.”

During the next four years, Ms. Adams was at the center of the rock revolution as one of Britain’s most acclaimed rock photographers — and one of the few women in the field.

“This business was our whole life,” she said in the 2008 Culturevoyage interview. “You’d be shooting all day, then go to a record company reception, have a few drinks and go on to a gig. There was no time for anything else.”

Ms. Adams shot more than 300 rock-star portraits for Boyfriend and later Fabulous magazine, including sessions with the Rolling Stones, David Bowie, Dusty Springfield, Bob Dylan and the Hollies. She photographed Jimi Hendrix in London clubs and in quietly contemplative settings before he became famous.

“I was in the Bag O’ Nails club in London to see him when he played his famous gig there in January 1967,” she told Culturevoyage, “and the Stones and the Beatles were in the audience. Word must have got out but I hardly knew who he was. He’d just been sitting at one of the tables and got up onstage.”

At the end of 1967, Ms. Adams abruptly stepped away from the heady rock scene she had chronicled.

“The attitude of the bands was changing, they were becoming more distant and drugs were taking their toll,” she said. “In photography, you can never relax. You always want to come up with new ideas, for yourself if for no one else. I think I was a very hard taskmaster to myself and it was becoming impossible to make things look different any more.”

She took a job with American Express, shooting pictures for advertising and brochures. She eventually settled on the British Channel island of Guernsey, where she had a general photography studio.

Her photos of rock stars remained stored away, and most of the people she met in her later work had no idea she had been at the heart of the London music scene in the ’60s.

Fiona Rose Pattinson Clarke was born Sept. 26, 1935, on Guernsey, where her parents, both trained musicians, operated a hotel.

She became interested in photography when a couple who were guests at the hotel gave her a Kodak Brownie camera. During World War II, she and her family moved to the British mainland for safety.

Ms. Adams studied photography at a London art school and later worked for a portrait photographer before spending four years with a government agency, taking pictures of buildings throughout London. She then spent two years in Australia, where she had a brief marriage. Little is known of her first husband, except that she took his last name, Adams.

Beginning in 1972, when she married Owen Le Tissier, a globe-trotting engineer, Ms. Adams shot scenic landscapes around the world. She returned to her native Guernsey in the 1980s.

Her husband died in 2011. Survivors include two children and a grandson.

After mounting small exhibits in Guernsey, Ms. Adams gained wider acclaim in 2009, when Britain’s National Portrait Gallery presented an exhibition of her rock portraits.

She retrieved her old contact sheets from a suitcase, uncovering images of what, more than 40 years later, looked like a lost civilization.

“For years I never really thought about what I’d done in the ’60s,” she said in 2008. “It was only [years later] that someone said to me why not mount an exhibition of your work?”