This week on MacBreak Studio, Steve Martin from Ripple Training shows us how to use shape masks to isolate color corrections in Final Cut Pro X.

As opposed to a color mask, which limits a color correction to a selected range of luminance and hue values (for example, the colors of a sky), a shape mask allows you to color correct a specific spatial region of a clip. It's ideal for focussing your viewer's attention on a person's face.

The mask shape, size, and position can be adjusted – although its shape is limited to basically a square whose corners can be rounded to make it circle, and whose dimensions can be distorted to make a rectangle or an oval. The edge of the shape has an adjustable feather to blend the color correction into the rest of the image.

Steve shows us how to use the shape mask to brighten a foreground face; or conversely, to darken a background. And, because the size and position of the mask can be keyframed, you can make it follow a subject that is moving in the frame.