In the 70's Ian Davison used a Hasselblad (borrowed from his employer - Rolls Royce!) for most of the pictures I saw him take - including the now lost Luneheads Mine, Smeltmill beck Cave, Dow Prov and Juniper Gulf. His 1970's Juniper Gulf picture with the ladder fully visible from top to bottom of a 200 foot shaft is probably one of the most iconic images in British caving in my humble opinion.