Chroma-keying is a compositing technique where a specific color in a video is rendered transparent. This allows us to insert different imagery (still or moving) behind our keyed video layer. This process is most commonly associated with the use of a green screen, in which the subject (often a person) is shot in front of a green backdrop. In this exercise, we will explore the basic post-production technique of chroma-keying by applying this to pre-made green screen footage we find on youtube. In Premiere, we will use the “Ultra Key” video effect to remove the green and create a layered composite of moving images.
We will first use this cat shot against a green screen to practice the technique. Using the ultra key to remove the green, we will insert a still image behind the cat to demonstrate the basic procedure:
After successfully removing the green, try stacking layers of footage. To do this, find green screen videos (make sure they are at least 720p- 1080p is preferable) and bring them into Premiere. Remove the green and build up a collage of moving images. This video can be short in length (between 20 and 30 seconds), but try and make it as dense as possible. When you are finished, export the video, upload it to youtube, and post it to our blog. The heading of the post should have your name followed by exercise 2 (Sean Miller Exercise 2) and the body should have the video. Have Fun!
Spring 2019 Digital Video 