Metabones CINE T ULTRA Speed Booster 0.71x Adapter w/ Positive Lock for Canon EF-Mount Lens to Sony E-Mount (MB_SPEF-E-BT3) Review

The Metabones CINE T ULTRA Speed Booster 0.71x is a focal reducer and adapter designed to mount Canon EF lenses onto Sony E-mount camera bodies. The 0.71x speed booster optics widen the field of view and increase maximum aperture by roughly one stop, making full-frame Canon glass more efficient on APS-C Sony sensors or providing a wider angle on full-frame E-mount bodies. The positive lock mechanism ensures a secure fit during professional use, and the support foot helps distribute weight when using heavier lenses.

This adapter sits in Metabones' CINE-oriented lineup, aimed at video shooters and cinema work where secure mounting and optical performance matter. At $324, it occupies the premium end of the EF-to-E adapter market, reflecting the speed booster optics and build quality. It's a practical choice for shooters who already own Canon EF glass and want to maximize its utility on Sony mirrorless systems without sacrificing image quality or handling.