Robert Guenette, a documentary filmmaker who helped change the way documentaries are made, died Friday. Guenette, who cofounded the International Documentary Association and produced "Monsters! Mysteries or Myths?" -- the highest-rated documentary in TV history -- introduced the innovation of using faux historic footage instead of relying on stock. Filming past events as though they had been captured by grainy newsreel cameras, Guenette lent a dramatic realism to documentaries lacked by his predecessors.