Reshoots! They're a dirty word, mostly because the only time the press takes notes of reshoots is when a production is troubled. But the reality is that for many filmmakers - including Woody Allen, who always schedules reshoots - they're a vital part of the process. They're key to the Marvel way of making movies, which is very much about finding the movie in the edit. While doing press for Guardians of the Galaxy (don't let Turtles beat it this weekend) I talked to Kevin Feige about this, and he told me that JW Rinzler's Making of Star Wars books made him feel better about their process.

I’m reading the part in Jedi where George is finding the movie in the cut. It happened in Empire, and it happened in Star Wars. You’ve heard about those famous early screenings where people were like, ‘Poor George. His career is over.’ That brings great solace to me when we screen our movies for the first time and they’re terrible and they’re a big mess. I remind myself to get calm and proceed. Post is my favorite part, because it’s easiest to find what’s wrong with the movie when you’re watching the movie.

For Feige it's important to know in advance that they will be doing additional shooting, no matter what. So while Avengers: Age of Ultron finished principal photography this week, it's pretty much a certainty that the cast will be getting back together for pick-ups, additions and tweaks. In fact Marvel already locked them in.

We always build in two weeks because the hardest thing about the additional photography is the actors’ schedules, wrangling the actors. So we just build it in. We’ve done some movies that have three days of reshoots, some that have fifteen days, twenty days if not more. Sometimes we know what we need by that point and sometimes we’re wrangling them anyway. There’s a shot in Thor: The Dark World we call the Three Continent shot. It’s one shot, with three different actors in it, that was done on three different continents. Additional photography is invaluable. Sometimes it’s to fix something that’s not working, but most of the time on our movies it’s two-fold: sometimes a better or more exciting idea will come along, or more often something will come out of the movie - because it’s too long or the movie is stronger without a particular beat or scene or shot, and you need connective tissue.

For Marvel these reshoots also offer a chance to put in easter eggs or small pieces that connect to the other movies. It's possible that cameos and larger universe shout-outs that will end up in Avengers: Age of Ultron won't even be shot until weeks before release. The famous shawarma scene in The Avengers was shot after the movie premiered.

Of course this isn't a filmmaking method that works for every filmmaker. Some are more precise in their initial shoot - it's hard to imagine Edgar Wright needing two weeks of additional shooting - but for some (and with a producer-driven studio like Marvel), it is a method that works.