Randall Webb, my mentor and friend, who has died aged 78, was a master of ancient and alternative photographic printing processes and an inspiring teacher. With Martin Reed, he wrote the definitive manual of alternative printing techniques, Spirits of Salts: Working Guide to Old Photographic Processes (1999). This book, also published in the US and translated into French, was a major influence in the revival of interest in antique image processing.

For more than 30 years Randall taught photography, in Richmond and Twickenham for Richmond Adult Education, and at colleges and schools including St Martin's School of Art, London, the German School, Richmond, and the American School, in Thorpe, Surrey. He worked with photographic groups including Framework, the Richmond and Twickenham Photographic Society and Group 6, and he created his own group, Group 1:20, which is how I came to know him. In 1997 he founded the quarterly arts magazine Network.

Born near Faversham, Kent, son of Alfred, a chauffeur, and Ellen, Randall went to Queen Elizabeth grammar school in Faversham. He did national service in the RAF, stationed in Pakistan, and became so fascinated by that part of the world that in 1957 he enrolled at the School of Oriental and African Studies, London University, on a degree course in Arabic. Randall then went into the travel business. After the death of his wife, Maureen (nee Blennerhassett), a journalist, in 1984 he left business for full-time photography.

Randall was revered, by those who worked with him and learned from him, for his faith in experimentation and for his only modest appreciation of rules.

He exhibited widely, starting in the early 1980s, and showed often in Richmond at the Orleans House Gallery and the Riverside Gallery. A major exhibition, Areas of Darkness, was held at Dimbola Lodge, Isle of Wight, in 1999.

Randall valued people deeply and was interested in small communities and changing ways of life. In 1992 he carried out a major documentary project, photographing Spitalfields, in east London, before the area's regeneration. The following year he began a four-year documentary study of the community of Knoydart, Scotland.

Randall is survived by his sons, Howard and Nigel, and two grandchildren.