In pictures: Dirty War: Special effects
Mass cordon

The extras were mixed around and asked to move further away from the camera several times, until there were five or six versions of the same crowd at different distances from the camera.

The closest shot was then layered over the next closest and so on - carefully painting out bits of background - until the entire street was full of people.

Click below for more images
1 2 3 4 5 6 7 8