Duffy’s work in fashion was a constant throughout his entire career. With a strong understanding of garments due to his history in fashion design gained from St. Martin’s. Duffy started to pursue photography in 1958 when he became assistant to Adrian Flowers during which time he did his first fashion shoot for The Sunday Times. Later that year he was picked up by British Vogue subsequently he became a regular contributor to French Elle Magazine. Throughout his career, he was a regular contributor to The Sunday Times Magazine, Cosmopolitan, Telegraph Magazine, Harpers Bazaar, Queen, Town, King, Nova, The Observer, Ritz, Tatler and many others.
Duffy worked with the key models of the period including Jean Shrimpton who he introduced to his close friend David Bailey. Also other icons of the era - Grace Coddington, Pauline Stone, Veruschka Von Lehndorff, Marisa Berenson, Jill Kennington, Bridgette Bardot, Ursula Andress, Pattie Boyd, Jennifer Hocking, Jane Birkin, Maggi Eckhardt, Barbara Miller, Amanda Lear, Joanna Lumley, Janice Dickinson, Kellie Wilson, Tania Mallet and many more.