Segments 4 through 6 of the BBC 11-part nature series. 40 camera teams were shooting at over 200 different locations all over the world for more than 5 years to get the pictures seen in the series. Each segment is followed by a sequence investigating the techniques and challenges of wildlife photography within that segment. Caves: Deep in an undiscovered world, including both poisonous and flooded caves, we find astonishing crystals; cave angel fish,...