Corinne Day: Photographer celebrated for her ground-breaking work with Kate Moss

Something very strange happened to the terminally ill fashion photographer, Corrine Day as she came closer to death.

She discovered glamour. Looking back, it's quite a shocking transformation. Shocking but inevitable at the same time. As Day's life drew to a close, her fashion photographs no longer dealt with the grubby realism of run-down tenements and the strange but fascinating ways of the inhabitants. Most probably she no longer wanted to look at that kind of thing. Almost overnight, rawness was replaced with refinement. It was a natural evolution.

Suffering the torture of a brain tumour – defiantly she had almost every grisly detail documented – was enough reality for Corrine Day. She turned her eyes to elegance. Her most recent work, fittingly entitled "Golden Years" for the October 2007 edition of British Vogue could easily have been taken by Horst. That's how accomplished, refined and breathtakingly beautiful this portfolio of photographs was.

Everyone who is anyone in fashion, and beyond, will know Day's legacy, her former celluloid signature: dirty, wasted, fresh, innocent, real. Council houses, not couture ateliers, were her natural domain. Day was an accidental photographer, an international glamour model with no formal training, but a faultless instinct which she followed until the day she died. Bored out of her mind, waiting for shots to be set up, Day picked up a camera and started to snap the scenes around her. When she was asked by The Face to come up with some fashion shots she trawled through the look books of the London hopefuls and came across a 15-year-old waif from Croydon called Kate Moss. It was a natural pairing, one that was to prove unbelievably fruitful for both. They were kindred spirits, two Cockney adventurers who fancied a mad day out. "I thought. She's like me," Day recalled years later. "She was cheeky, and I really liked that."

The snaps taken on Camber Sands were sublime in their innocence. Moss was running around in a feathered headdress and shod in Birkenstock sandals. "I was just having a laugh," Moss remembered. "Corinne just wanted to bring out everything I hated when I was 15. My bow legs, the mole on my breast, the way I laughed."

This daft adventure, which ended up being featured in the Third Summer of Love editorial for The Face in 1990, propelled both Day and Moss into fashion wonderland. It was a seminal moment, later to become a photographic exhibition at Gimpel Fils entitled simply "Fifteen". They both became world famous, and neither of them were ever to look back.

Day became the uncrowned queen of a new trend. The media gave it a name: Heroin Chic. After The Face came the call from Vogue. In 1993, the new editor, Alexandra Shulman, formerly of GQ, wanted to add some reality to the proceedings. She had a quest to inject more affordable, high street clothes into the magazine and commissioned Day. So the portals of Condé Nast saw something they hadn't entertained before: grubby carpets, visible pubic hair, American tan tights, a PVC sofa and a bare radiator. The model, Moss, looked bleakly into space. The New York Times described her look as "very young and very dead".

It did, of course, cause controversy; some may say of the wrong kind. Susie Orbach, a staunch feminist, said they were "just this side of porn", while the Cosmpolitan editor Marcelle D'Argy Smith called them "hideous and tragic". In truth, the trend, also referred to as "dirty realism", jarred the flow of the Vogue fashion pages and looked utterly out of place.

Following her diagnosis of a brain tumour in 1996, Day turned the camera on herself. Even in periods of prolonged, intense pain and incredible distress she asked for her surgery journey to be recorded. In 2000 she staged an exhibition at the Photographer's Gallery simply entitled "Diary". It was an intermittent photographic record of herself and everyone around her. By then she was extremely ill and was acutely aware of the value of friendship. In a nutshell: the people around her were pulling her through. "Good friends make you face the truth about yourself," she said, "and you do the same to them, as painful or as pleasurable as that is." She held an exhibition which celebrated the life-enhancing qualilties of friendship, epitomised by Tara, her best friend.

Corrine Day's legacy is her honesty, the turnaround in her style a natural consequence of what she was going through. "Fashion photography has always been about fantasy," she said. "I wanted to take it in the opposite direction." Later, in the exquisite Golden Years shoot, her final curtain call for British Vogue, it is telling that one of her most beautiful shots is of a model, wearing a curvaceous black evening dress standing on the platform of the London tube. Chiffon is flying. The train is speeding past, leaving the station.

Corinne Day, model and photographer: born 19 February 1962; partner to Mark Szaszy; died 27 August 2010.