What is a key step when using the ultra key effect for green screen?

When working with the ultra key effect for green screen, changing the setting from default to aggressive, if needed, is crucial. The ultra key effect is designed to remove a specific color background—in this case, green—allowing the subject to stand out.

Starting with default settings is often a good baseline; however, in many situations, particularly when dealing with varying lighting and green screen quality, the default may not effectively remove all unwanted green hues or may leave artifacts. By adjusting the key settings to aggressive, you enhance the algorithm's capacity to isolate the background color, making it more effective at eliminating any residual green spill or imperfections in the keying process.

Therefore, understanding the settings and when to modify them is key to achieving a clean composite. This step can significantly influence the final output quality of the video, ensuring that the subject is properly isolated against the new background you wish to use.