Herzog's four-man crew was allowed into the cave for six four-hour shooting days, and was confined to narrow walkways lit only by small battery-powered lights (standard film lights emit heat that could damage the paintings). The tiny 3-D camera had to be rebuilt between shots to accommodate different lenses, because the men couldn't physically move the camera much within the cave. The resulting effect is wonderfully intimate: Rather than causing the paintings to pop forward in front of it, the 3-D enhances perception deep into the frame. The low lighting even accentuates the experience, mimicking the conditions in which the paintings were initially made and seen, and drawing out what Herzog sees as their latent cinematic potential.