Pro movie directors do this too. In fact, it's so ubiquitous, there are several millions of dollars per movie project that go strictly into editing. One of the

Pro movie directors do this too. In fact, it's so ubiquitous, there are several millions of dollars per movie project that go strictly into editing. One of the best known examples of this, from Peter Jackson's The Lord of the Rings trilogy, notably did not even have a single real Balrog appear in their raw footage. It's a shame he resorted to cheating - but what's strange is the trilogy is universally acclaimed as one of the greatest movie trilogies of all time.