Letterbox

Letterbox converts a finished image into another raster, such as a wide frame for an HD monitor or horizontal footage for a vertical composition. The node actually changes output dimensions rather than merely drawing bars over an unchanged image.

Choose target Width and Height. Auto Resolution gets dimensions from the Resolve timeline or Fusion Studio Frame Format; disable it for an explicit output size. Keep Pixel Aspect X/Y at 1/1 for ordinary square pixels. Pixel aspect describes pixel shape, so an accidental change affects displayed geometry.

Envelope fits the image to width. If the resulting height is below the target, top and bottom borders remain; if it exceeds the target, some content extends beyond the target frame. It is therefore incorrect to say Envelope always fits the whole image. Compare the actual aspect ratios.

Pan-and-Scan fits the image to height. When the resulting width exceeds the output width, Center selects the visible horizontal region. This is useful for vertical versions of a wide shot. If width is insufficient, the mode’s name alone does not guarantee a fully covered raster.

Center does not operate in Envelope. In Pan-and-Scan, use it to choose framing and follow a subject while resolution stays fixed. BMD discourages animating controls that change physical image dimensions; separate per-frame format changes from normal framing motion.

Compare Filter Method at actual scale: softer filtering can lose fine detail while sharper filtering can ring around contrast. The PNG shows Nearest Neighbor, Box, Linear, Quadratic, Cubic, Catmull-Rom, Gaussian, Mitchell, Lanczos, Sinc and Bessel. The manual also describes the conditional Window Method menu for Sinc/Bessel.

Clipping Mode concerns processing boundaries and the image domain. This node’s capture shows None and Frame. Do not add Domain merely because other Fusion tools offer it. Review output dimensions, Viewer alpha, boundaries and the downstream node.