The T CINE Speed Booster ULTRA 0.71x Adapter from Metabones allows a ARRI PL-mount lens to be mounted onto a camera with a FUJIFILM X-mount. The adapter's optics maximize the connected lens's apparent angle of view by a factor of 0.71x while providing a one-stop increase for the camera over the lens's aperture range.

If a lens designed for 35mm film or similarly sized full-frame camera sensor is connected to a camera with a smaller sensor, it would project an image larger than the sensor was made to render. Able to capture only the center portion of the projected image, the effective angle of view of the lens would be narrowed, creating an in-camera "crop factor." The T CINE Speed Booster ULTRA 0.71x adapter condenses the light from a lens designed for 35mm film or "full-frame" camera sensors and projects it onto the sensor. This allows the camera's sensor to utilize more of the light gathered by a connected lens, which effectively reduces the crop factor while making available to the sensor an additional one f/stop of light for each of the lens's f/stop settings.

This adapter is constructed from aluminum for durability while minimizing weight, and its mounting rings are made with brass to further prevent wear and tear. The internal optics feature five lens elements in four groups and are designed to provide optical clarity as well as color fidelity. The detachable tripod foot is Arca-type compatible and features 1/4"-20 threads.