Removes areas of a layer based on differences with another layer. This works best with stationary shots, where you film a clean plate of the background, keep the camera locked off, and then film your subject. The Difference Key then compares each pixel of the two shots, and any pixels that remain the same are removed by the key. The background, which is the same in both shots, is thus removed, and only the subject remains.
- Source Layer: Choose any layer from the timeline. The selected layer will be compared to the current layer to generate the key.
- Blurred Comparison: Applies an invisible blur to each layer before calculating the key. Used judiciously, this can help to overcome difficulties like grain or noise in the footage.
- Threshold: Defines how different each pixel must be in order to be removed.
- Softness: Feathers the edge of the key to create a softer edge.