The Previzion System is a pre-viz and compositing film-making tool that incorporates green screen photography with backgrounds on-the-fly giving the director a completed composite in real time. The common wisdom has been for several years that ultimately the assistant editor on a project will be trained to do a lot of the green screen composites that come up on a show thereby reducing the amount of work done by visual effects houses. The Previzion system begins to sidestep that idea and allows the user to pre-composite on set thereby greatly reducing the labor required for post production compositing. This will prove a great asset to editors as they will have clean, possibly final versions of green screen shots that they can rely upon while cutting the film.