Working with Composite Modes

Final Cut Pro composite modes determine how the brightness and color of one clip visually interact with those of another clip layered beneath it in a sequence. When you edit a clip into your sequence, it defaults to the Normal composite mode, meaning that it is a completely opaque layer that does not blend with the layers beneath.

How Composite Modes Affect Images

Composite modes mix colors from overlapping images together based on the brightness values within each color channel in an image. Every image consists of red, green, blue, and alpha channels (or one luma and two chroma channels in the case of Y′CBCR component video). Each individual channel contains a range of brightness values that defines the intensity of each pixel in the image that uses some of that color.

The effect that each composite mode has on objects that overlap in the Canvas depends on the range of color values within each object. The red, green, and blue channels (or Y′CBCR channels) within each overlapping pixel are mathematically combined to yield the final image.

These value ranges can be described as blacks, midrange values, or whites. These regions are loosely illustrated by the chart below.

Figure. Diagram showing the gradation of change from blacks to midrange color values to whites.

For example, the Multiply composite mode renders color values that fall into the white areas of an image transparent, while the black areas of the image are left alone. All midrange color values become translucent, with colors falling into the lighter end of the scale becoming more transparent than the colors that fall into the darker end of the scale.

Important: Final Cut Pro composite modes work in conjunction with a clip’s Opacity parameter. The composite mode you select determines how the color values of one clip interact with those in the clip beneath it. Additional changes made to a clip’s opacity can lighten or intensify this effect.

Figure. Canvas window showing an image in normal composite mode with the opacity set at 50 percent.

Applying Composite Modes to Clips

Applying different composite modes to layered clips in a sequence is easy. The main thing to remember is that composite modes affect the interaction between one layered clip and whichever clip is underneath it in the sequence. Clips that are above a layered clip using a composite mode are unaffected.

To apply a composite mode to a clip in your sequence
  1. With two layered clips edited into your sequence, select the topmost clip in the Timeline.

  2. Choose Modify > Composite Mode, then choose a composite mode.

    See Composite Modes in Final Cut Pro for information on the different modes.

  3. Move the playhead over these two clips to see the interaction between the two clips in the Canvas.

    Figure. Canvas window showing the Screen composite mode on the upper of two clips, with the opacity of both set to 100 percent.

You can quickly view or change a clip’s composite mode while working in the Timeline. This provides a fast alternative to choosing a different composite mode from the Modify menu.

To view or change a clip’s composite mode
  1. Control-click a clip in the Timeline, then choose Composite Mode from the shortcut menu.

    Figure.  Shortcut menu showing the Composite Mode command and a submenu of available composite modes.
  2. If you want to change the clip’s composite mode, choose a new mode from the submenu.