How to Green Screen an Interior Car Reflection on Glass

The use of a green screen backdrop enables filmmakers to add special effects to what might seem an ordinary scene.

Filmmakers often use the "green screen" technique for special effects shots added in postproduction. By filming actors or vehicles in front of a bright green backdrop, they can use editing software to digitally replace the distinctive color with another image, such as an exotic background that would be impossible to create on a set. Creating backdrops seen through the windows of moving cars is one of the more fundamental uses for a green screen and "keying" software, since the actual cars may not be able to drive exactly where the director would like.

Things You'll Need

• Keying software

Instructions

1. Set up your green screen behind the car windows you intend to work with. This may involve either placing the green screen inside the car, up against the windows, or beyond the car (from the camera's point of view). Make sure you are not covering anything you want to appear, such as the backdrop behind the car.

2. Film the scene that the car is involved in, utilizing the green screen in place of the desired interior reflection.

3. Film or digitally create the "replacement" footage, in this case whatever interior reflection you want shown on the window glass.

4. Edit your footage, using the keying software to replace the green parts of the primary shot with the replacement footage. This may require careful adjustment of the replacement footage. For example, the car's window frame may cover an important element of the reflection at first placement.

5. Touch up your merged footage to realistically account for the reflections on the glass that may appear in the initial footage. Ensure the reflections are appropriate to the fullest extent possible, whether that means using the keying software to tweak the replacement footage to account for them, or digitally erasing them if they show something undesirable, such as a reflection of the camera crew.

Tips & Warnings

• Make sure your editor has the proper knowledge and equipment to mesh the green screen footage, particularly if you are working on a low-budget project.

• Film test footage using different green screen techniques if you have the capability and budget, in order to determine the best approach to placement of the screen, for instance.

• Proper lighting is critical to any film shoot, including one utilizing a green screen.

References

• Hollywood Camera Work: Green Screen Plates
• Post: The Keys to Shooting Greenscreen