Here is a geologist getting ready to take a photograph down into the Pu'u 'O'o vent. Notice that she is wearing a protective helmet and a gas mask. This particular vent is the source of both spatter and caustic gases and her caution was wise.
These are time-lapse cameras, and they probably get to see more exciting volcanic events on Hawaiian volcanoes than people do. This is because they can sit out in the rain and mist for days at a time. These particular cameras are actually super-8 movie cameras set to shoot one frame every few minutes or so. They are mounted in protective boxes constructed out of old ammunition boxes. The far box has been opened to show the camera whereas the near one is sealed up. Often two are employed at a single viewing location, with one set on wide angle and the other zoomed in on an active vent.