How to Key a Green Screen Cleanly in Your Editor

Start with the cleanest source you can

Clean keying in the editor starts on set, not in the software. If the green is even and the subject stands clear of the cloth, the default key settings often work on the first try. Spend your time on the shoot and the edit becomes short.

Import the clip and look at it full size before you add any effect. Find the brightest and darkest spots of green in the frame. Those two patches tell you how much range the key has to handle.

Pull a key with a light touch

Use the eyedropper on a flat area of green, then raise the tolerance until the background drops out. Stop as soon as it does. Pushing the tolerance further starts to chew into the subject and eats soft edges like hair.

Turn on the matte view to see what the tool is keeping and removing. White is kept, black is cut, and gray is halfway. A clean matte is mostly pure black and white with a soft band only at the real edges.

Clean the edge with a few small tools

A slight choke pulls the matte inward and hides a thin green line around the subject. Use it in small amounts, because too much erodes hair and fingers. A light edge blur softens the hard cut without making the person look like a sticker.

Use a garbage matte to crop out areas the software should never see. Stands, cables, and the floor below the cloth all become irrelevant once you mask them away. It runs faster than asking the key to solve the whole frame.

A clean key is mostly a clean shoot with a gentle hand in the software.

Fix the little things that remain

Light wrap blends a hint of the new background onto the subject's edges so they do not look pasted on. A very small amount goes a long way. Push it too far and the person glows.

Color the subject to match the new scene before you call it done. A face lit for a bright room looks wrong against a night background. A quick grade on skin and shadows sells the shot more than any key setting.

Key takeaways

• Shoot an even screen so the default key nearly works.
• Pick the green, then raise tolerance only until the background drops.
• Watch the matte view and keep hair detail.
• Use a small choke, edge blur, and a garbage matte.
• Add light wrap and a grade to blend the subject in.