Martyn graduated with a degree in photography from Harrow College in 1974 before assisting top photographers and eventually going freelance. He became immersed in the New Wave music scene, photographing iconic acts like Blondie, The Jam, and The Cure. His work has been featured in Blondie in Camera 1978 and The Jam: About the Young Idea (2015).

In the late 1970s, he began contributing to The Sunday Telegraph Magazine, shooting features of influential artists while producing automotive and travel stories for Car Magazine. Now embracing digital platforms, he is an active photo-blogger, creating travel features and content for media groups across the UK, Europe, and the U.S., while also preserving his vast archive of rock photography.