“Letterboxes” an object by masking it horizontally at the top and bottom to simulate different video and film aspect ratios. Because the image is masked, the layer beneath it in the composition (or the background color of the project) appears in the border space above and below the image. You can add a border to the masked image and customize the color and size of the border.
Adjust this filter using the parameter controls in the Filters Inspector:
Aspect Ratio: Sets the aspect ratio of the mask. Values include 1.66:1, 1.70:1, 1.78:1, 1.85:1, 2.35:1, 2.55:1, and 3.00:1.
Offset: Sets the position of the mask relative to the Y center of the layer. Values range from –1.0 (the bottom of the layer) to 0 (the center of the layer) to 1.0 (the top of the layer).
Border Size: Sets the thickness of the border.
Note: The border has no effect on the aspect ratio mask. The Border Size control merely adds a frame at the top and bottom edges of the filtered image.
Border Color: Picks the color of the border. Color controls can be expanded with the disclosure triangle to include Red, Green, Blue, and Opacity sliders to more precisely select the color of the border.
Mix: Sets the percentage of the original image to be blended with the letterboxed image.