Fujichrome 100, OM-2S, 24mm lens, B-setting at f/2.8, 3 Press 25B flashbulbs, tripod.
"This is a great example of a multiple flash shot. Here, the open lens is capped between each flash, allowing the caver to turn his light on and move down the passage. Once repositioned, the cap is removed and another flash is set off. This image shows the same caver three times."