From the "After The Hunt" VFX Breakdown, by Frame by Frame
When people see a relatively innocuous shot from a movie of a city street, then see that it was an elaborate visual effects shot (either shot against a greenscreen or at a studio backlot), sometimes they wonder “Why didn’t they just film that at a real location? Wouldn't that have been easier and cheaper? Why resort to camera tricks?
Generally speaking, film crews need levels of control over the environment to a degree that is difficult for non-industry people to understand, which makes shooting on location sometimes not the best idea for a film production.
Here's a basic list of some of the reasons they didn’t “just shoot it at a real location” (there are plenty more):
- ultimate control for lighting and sun position, time of year
- location weather unsuitable for the film, either narratively or logistically
- repeatable action for multiple setups
- permissions and permits unreasonable or impossible
- disruption of a community (closed businesses, car and pedestrian traffic) for days or weeks at a time
- safety of crew
- location accessibility for countless trucks and gear and dozens of crew members
- availability of actors and crew
- no location fits the storytelling needs of the production, or the location would require massive structural modification to fit the storytelling needs (period picture, science fiction, alternate reality, etc.)
- additional photography (“re-shoots”) required but location no longer available or weather/season is totally different
- location shooting is much more complicated and time consuming than studio shooting
