We asked the editor of 'Downsizing' if he misses cutting film

Editing a film used to involve exactly that: Cutting up photographic film and sticking it back together. But like most industries, the digital revolution has shaken up movie editing -- to the point that editor Kevin Tent cut part of an Oscar-winning movie while sitting on a train.

Tent is a regular collaborator with acclaimed director Alexander Payne, working together on films such as "Sideways" and "Nebraska". The pair huddled over a laptop to do some rough edits on 2011's "The Descendants", which would go on to win an Academy Award for its screenplay, while they rode a train through Italy to George Clooney's Lake Como home.

Now they've collaborated again on "Downsizing", a new sci-fi comedy starring Matt Damon, Kirsten Wiig and Christoph Waltz. Out now in the US, "Downsizing" is a comic look at a world in which people solve the ecological issues by miniaturising themselves -- only to find that even when they're teeny-tiny, their problems still loom large.

I chatted with Tent on the phone from LA to talk about how movie editing has changed since he began his career working for B-movie king Roger Corman in the 1980s.

"I learned on Moviolas," says Tent, recalling the large editing machines that editors used for much of the twentieth century to fast-forward and rewind physical film through an array of complex reels. Now, Tent does all his editing digitally, using Avid editing software. Does he miss the old-school glamour of real film? "No!" Tent laughs. "I used to be a romantic, but now I'm not."

Compared to film editing, digital editing allows a much greater freedom. Working with physical film meant old school editors had to be decisive in their choices. "It was like a game of chess," explains Tent. "If you wanted to pull a scene out and change it you had to think several moves ahead".

Among the clever features in Avid is an option called ScriptSync, which shows the script on screen at the same time as the relevant footage. "You can click on a line in the script and see the line reading by the actor," says Tent, "which is a feature Alexander loves."

One aspect of "Downsizing" that was new to Payne was the heavy use of visual effects. That meant Payne and Tent had to make editing decisions relatively final so each scene could be passed onto the effects teams to composite the small and large characters together. Fortunately, advances in digital technology mean that the editing and effects teams could work side-by-side with at least some flexibility to take scenes out and put them back in.

Tent and Payne also worked together on scabrous new comedy "Crash Pad", which Payne produced and Tent directed -- his first directorial outing after being credited as such on two Roger Corman productions in the 1980s. Funnily enough, "Downsizing" cinematographer Phedon Papamichael also worked with Corman's low-budget, high-output film factory. "It was a great place to learn", remembers Tent, who honed his editing skills cobbling together bits of other Corman films to pad out low-budget titles like "Frankenhooker" and "Not of This Earth" -- check out his enormously entertaining reminiscences of those days.

Fond as he may be of those free-wheeling days, Tent is happy to have ditched physical film editing for the digital equivalent. Although he does admit that handling film reels and machinery was more physically active than using a computer. "Now you just sit down all the time," he laughs.

"Downsizing" is in theatres in the US on 22 December and opens in UK cinemas on 19 January. "Crash Pad" is out now on DVD and online.

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