How to Use the Chroma Key Backdrops

Chroma key backdrops are integral tools in film and video production. They make extreme or impossible locations and effects attainable. Some of the biggest blockbusters in modern movie history have used chroma key technology; James Cameron's "Titanic", Peter Jackson's "The Lord of the Rings" and George Lucas' "The Empire Strikes Back" all include extensive chroma key work. Take the time to set up and light the backdrop properly and you'll end up with seamless results.

• 1

  Choose the chroma key backdrop that is right for your project. Blue drops are easier to integrate into a set and separate from a person's skin tone. Green drops are easier to see in post production, which makes it less likely for pieces of the backdrop to slip through unnoticed. When considering size also consider material. You can buy fabric, seamless back drops, portable screens, or chroma key paint that can be applied to any smooth, even wall.

• 2

  Set up the fabric backdrops with a frame and c-stands, making sure that the fabric is taught across the frame so there are no wrinkles that will cause shadows, and leaving adequate backdrop draped on the floor. With any chroma key material, you will need enough space to light around your subject without fall-off, a dramatic difference in light, in the shot.

• 3

  Light the backdrop evenly, without hot spots or shadows, before the subject is placed on the chroma key.

• 4

  Light the subject. Place the person or object on the backdrop as needed and light to match any accompanying video, or as required for the intended effect.

• 5

  Place back lights on either side of the subject to keep the blue or green backdrop reflection from spilling on to the subject.

• 6

  While in post production, use the chroma key function on your editing software to replace the blue or green backdrop with the intended image.