A news presenter is standing in an empty room painted green. You are watching them in a gleaming studio. The technique is forty years old and it is available to anyone with a bedsheet.
Lighting is the whole job
Almost every bad key is a lighting problem being blamed on software. Three rules:
- Light the screen evenly and separately from the person. Two lights at forty-five degrees.
- Keep the presenter well away from the screen — at least a metre and a half. Close to the screen means green bouncing onto them, and no software removes that cleanly.
- Light the presenter on their own, from the front. If their only light is bouncing off the green, they will have a green rim.
A wrinkled cloth is a worse problem than a cheap one. Wrinkles make shadows and shadows are a different shade of green, which is exactly what a key cannot handle.
Pulling the key
Click the green, then turn on the key preview — the view that shows the matte itself rather than the result.
You want the background pure black and the person pure white. Any grey is where the key will fail. Adjust until the grey is gone.
Then raise spill suppression until the green rim on shoulders and hair disappears, and soften the edge until the cut-out look goes.
Choosing a backdrop
A still image, a video, or a 3D studio set. Marketplaces are full of broadcast-quality sets for very little.
Match the perspective. A backdrop shot from a low angle behind a presenter framed from a high one looks wrong even if the key is perfect. And match the colour temperature — a warm room behind a coolly-lit presenter never quite convinces.
If you cannot hang a screen
Background blur and background removal work on an ordinary room with no cloth at all. Not as clean as a well-lit green screen, but entirely good enough for an interview or a desk segment, and they work in a hotel room.