Place a person or other subject two to three feet in front of a solid background. A background in a kelly green color is ideal for the most professional results. However, you can use any solid color. A royal blue color background is also a solid choice. Wrinkle-fee muslin sheets and painted walls work well as backgrounds.
Evenly light the background and the subject using a professional studio lighting kit. If you do not have access to professional lights, move outside in a sunny area that is evenly lighted.
Film or photograph the subject in front of the background. It's important to keep the frame of your photo or video within the solid background.
Import your video or photograph into a project within your photography or video editing software. The program should have an effect option titled chroma key, color key or both. Select either effect.
Choose a new video or photo background and import it into your project to place as a layer behind the original video or photo. Click on the solid background of the original video or photograph with the chroma key or color key tool. Do not select the subject. While instructions may vary from program to program, most software uses a similar process.
Adjust the keying slowly as you watch the solid background disappear and the new background appear around the subject. You may need to use several additional effects offered in your software such as feathering to smooth out any edges around the subject and clean up any flickering from the original background.