Owen Newman and Amanda Barrett have spent 14 years documenting the lives of big cats - meaning lions and such rather than obese tabbies. Their first subject was the cheetah, and since then they've tracked down some of the rarest African wild cat species, including the serval and the caracal.

The footage they've shot under difficult circumstances is incredible. It's also interesting to glimpse the human stories behind the camera and the specialised filming techniques they have developed over the years.