Desc: Masters of Stone IV - Pure Force: Directed by Eric Perlman. With John Bachar, Dave Barlia, Tommy Caldwell, Alexander Huber. Masters of Stone IV - Pure force is a documentary about rock climbing that takes place in Tuolumne Meadows and El Capitan. It was directed by Eric Perlman in 1997 and produced by Perlman Productions. It is a part of the series Masters of stone (4/6). It features Dan Osman, Ron Kauk, Chris Sharma, Alexander Huber, John Bachar, Katie Brown and others.