The magnificent Jane Bown, the Observer’s veteran and legendary photographer who recently said: “I spent my whole life worrying about time and light,” has died just four months short of her 90th birthday. The Observer editor, John Mulholland, called her “part of the Observer’s DNA”.

She joined the Observer in 1949 and, resisting all offers from other prospective employers, continued to appear in the office every week for more than half a century, working on 35mm film to the end, meekly waiting for assignments, and turning in dazzlingly beautiful images for news stories and features. She was particularly well known for portraits of the rich, famous, infamous and unknown. Many became trademark images of her subjects, including her definitive portrait of the playwright Samuel Becket, glaring like a caged eagle, whom she cornered in an alley beside the Royal Court theatre as he tried to make his escape.

She was made an MBE in 1985, a CBE in 1995 and, although by then too frail to take photographs, she last appeared in the Observer offices in August.

Mulholland called her one of the greatest photographers of her generation. “During more than 50 years working for the Observer, she produced some of the most memorable and insightful images of prominent cultural and political figures taken during the 20th century – from the Queen to the Beatles, Samuel Beckett to Björk, John Betjeman to Bob Hope, her beautifully observed pictures have become part of our cultural landscape. She is part of the Observer’s DNA – her contribution to the paper’s history, as well to Britain’s artistic legacy, is immense, and will long survive her. She was loved by her colleagues and adored by our readers. We will miss her hugely.”

Photographer and former picture editor Eamon McCabe said: “Nobody has taken so many wonderful photographs of so many great faces, with such little fuss as Jane Bown. She was a reluctant star, hating the attention of being well known herself.”

When other photographers of her generation were selling their archives for small fortunes, she donated hers to the Guardian, parent company of her beloved Observer. Archivist Luke Dodd, who became her friend, her biographer in a recent film made with Michael Whyte and, as she became more frail, was even permitted to become her assistant on assignments including Charlie Watts of the Rolling Stones, said she was without vanity. “It was always about the picture, not about her, and she worked with what she had. That famous Beckett image, which has been reproduced so many times, was the third of five frames.”

Another former editor, Donald Trelford, once called her “a white witch” for her ability to get under the skin of her subjects. Bown’s motto was “photographers should neither be seen nor heard”, she carried her camera in a wicker basket, worked without extra lights, and liked to be done and dusted within 10 minutes.

Dodd said she had perfected a disguise as a respectable little middle class woman from Hampshire, which fooled many – though he recalled that she once called to heel the film star and comedian Robin Williams, who was bouncing about his hotel room showing off and entertaining his entourage, with a single crisp sentence.

She had been frail for some time and in hospital after a recent fall. She died on Sunday at her home in Hampshire, with members of her family around her.

“She was herself to the last. I was speaking to her yesterday,” Dodd said. “I said I might come down on Monday, and asked her daughter who would be there. This little voice came from the background and she said ‘not me’.”