John Cornwell was a freelance photographer who took many photographs of collieries, mostly in south Wales and the English Midlands, both underground and on the surface, during the 1970s and early 1980s. He perfected a method of underground photography using the standard colliery lighting and was able to photograph coal faces, roadways, shafts and equipment with amazing clarity. In addition to photographing working mines he also recorded abandoned mine workings, above and below ground.
John Cornwell was also well respected in the broader field of industrial archaeology. He published a number of books on Welsh and English collieries.
The copyright of his south Wales images are now owned by National Museum Wales.