The procedures and tools used to pull a key depend on the source material you are working with, and on the complexity of the task. For example, sources shot under ideal lighting conditions with good contrast between the key-in and key-out content can be done very quickly. Other sources, with varying lighting conditions, fine detail at the edges of the key, dramatic camera movement, and other problem areas can take much longer to produce a clean result. Make sure you understand what keying task, or keying tasks, need to be performed so you can select the keying tools and the order of the keying tasks that will produce the best result.
This chapter provides some keying scenarios using different keying tools to help you understand how to use the tools. When you pull a key, you may not necessarily need to perform all the keying scenarios in the order presented. Moreover, there will be instances where one tool may provide you with a clean key, and other times where a combination of keying tools will be needed to generate the desired keying result.
