Utilizing green or blue screen (chroma key) in your video projects is a great way to introduce a professional and stylish look to your video productions. Having the ability to change your subject’s background in post production will give you limitless options when it comes to your final product. There are a wide variety of chroma key backgrounds to choose from that will give your video production a polished look similar to larger video productions.
The basic idea of green screen production is simple: setup a green screen, shoot your talent in front of it, then remove the green in your video editing software and replace it with your chosen background in post production. However, getting a precisekey from your footage can be a trial and error process that could cause frustration if the original videois not shot correctly.
Here are a few simple tips you can use to help make your green screen background production as troublefree as possible:
- How to choose a chroma backdrop
a. A chroma key background can be any color as long as it is not contained within the foreground elements you would like to keep in the scene. Most video productions utilize either a green or blue screen. A clean key can be achieved with either color, but you will want to take into account the color of clothing your talent will be wearing and also make sure nothing in your scene closely matches the color of the background color you are trying to remove.
b. The more consistent and true your color is, the better you will be able to key the color out of your background footage. If you are using a linen or fabric backdrop, try to minimize the wrinkles and shadows in the cloth.
- Illumination
a. This is probably THE most important aspect of a good green screen video production. Having a well lit, consistent background color is key (no pun intended) to being able to remove the background seamlessly from your shot.
b. Having multiple lights will help to even out the lighting in your scene. Fluorescent lighting and outdoor/sunlight provide good consistent and smooth indirect lighting to your chroma key background.
c. Illuminate your subject fully with soft lighting. You may also want to try to add a spotlight pointing at the back of your subject. This will help to cleanly “cut” your subject from the background and will result in a cleaner key.
- Subject Placement
a. Make sure your talent is at least 4 steps in front of your chroma key backdrop. This will help minimize shadows falling onto the green screen and will minimize color spill. Color spill occurs when the reflected green from your backdrop “spills” onto your subject and causes the color of clothing or skin to change hue to match the background. This can cause problems for your color key software and results in rough edges on the final production.
- Video Camera Settings
a. If you have access, try to shoot with the best HD camera possible. A camera that has manual controls for shutter speed, ISO and aperture are best. Set the ISO on your camera to 100 or 200 which should help to reduce signal noise and will smooth out the backdrop in your video.
By following these simple rules and techniques, you should be able to create a clean shot that will allow you to easily remove the chroma key from your background. Now you can replace the green screen with a virtual background or other video background. Have fun!