Here’s a look at how I created one of the FX shots in the Wasteland trailer. Tom, the director, wanted to see the central character, Scott (Shameer Seepersand), walking along a deserted dual carriageway to show his isolation in the post-apocalyptic world.

We started by shooting the A50 from a bridge (image 1). Traffic was light, but we were never able to get a clean, car-less shot. (While filming we were interrupted by a couple of blokes from the Highways Agency who wanted to cover their arses in case of accident, so gave us a safety briefing: “Be careful when you cross the road, lads.”)

The next day we drove around looking for a footpath or cycle path with similar tarmac to the A50 which could be shot from a bridge to get the same elevated viewpoint. Having located one, we filmed Sham walking (2).

Shrinking Sham down and feathering the edges of his element into the shot was the work of moments (3), but the illusion wasn’t complete until this element had been colour-corrected to match up the tarmacs.

Next the cars had to be erased, which I achieved partly by overlaying cropped sections from later in the footage (when the cars had moved on, leaving a space behind) and partly by exporting a frame to Photoshop and using the clone tool. The former technique is preferable because using a motion element retains the movement of picture noise; the lack of this movement can be an FX giveaway. Therefore I kept the Photoshopped sections small – just way in the distance where the cars were tiny.

At this point (4) the shot is essentially complete, but I added some extra touches in the form of smoke elements from an FX library, a faint one in the distance (top left) and one on the van which I had left frozen in the picture as if it had been abandoned. I also duplicated the van’s smoke and distorted it to create a shadow for that smoke (5).

All images copyright 2011 Light Films.