The film was shot in one take near Loch Doyne in Scotland.
They used take 40 – the last take of the shoot, filmed at 8pm.
They blocked out the filming first at Hyde Park.
Cameraman George Richmond sat on the back of a rickshaw and was pulled along the rocky path by two grips. The camera and crew survived one nasty tumble. Richmond's steadicam credits include Quantum of Solace, Burn After Reading and The Golden Compass.
At the end of the first day they had not completed a full take. This was because the wall of TVs was positioned two metres out. It had to be dismantled and rebuilt.
Director Jamie Rafn describes Robert Carlyle as "an utter genius" with "abundant natural charisma. He just filled the screen and possessed it."