We also had a camera on top of the mountain, a camera below, and a camera on the next- door mountain a quarter of a mile away picking them up as they went down. So to do this, not only do you have to have people who can climb 20,000ft, you also have to plan the expedition like a mountain ascent, leaving camps halfway up the climb with camera equipment. And then, when you do it, you only have one shot - everything has to work first time.'
Chris Powell, series producer of Voyager (ITV Thursday), on adventure films: 'The problem of adventure films is there's a huge amount of 'seen it all before' - it's almost like reinventing the wheel. You can go in two directions: 1) Come up with a story that is even more fantastic than any others; 2) Use new production techniques and better technology. For example, in this Thursday's film, 'The Most Dangerous Jump in the World' (in which two men parachute off the 6,000ft Great Trango Tower cliffs in Pakistan), we had seven cameras in total. Glen jumped first and had a 7kg camera attached to his helmet, facing backwards to pick up Nick; and Nick had one facing down and picking up Glen.