Metabones CINE Speed Booster Ultra 0.71x EF-Mount to E-Mount Lens Adapter

Metabones is a Vancouver-based manufacturer specializing exclusively in lens adapters for hybrid and cinema mirrorless camera systems. The company is widely associated with the Speed Booster line, an optically active adapter family developed in collaboration with Brian Caldwell that compresses the image circle of a full-frame lens onto a smaller-format sensor—delivering approximately one stop of additional light and a wider effective field of view. Beyond the Speed Booster, Metabones produces conventional Smart Adapters for combinations such as Canon EF to Sony E, EF to RF, and PL to various mirrorless mounts, with electronic communication for autofocus, aperture control, and image stabilization where supported.

The company's design philosophy emphasizes mechanical precision and sustained firmware development over feature breadth. Mounts are machined from chromium-plated brass or anodized aluminum, with tolerances tight enough to maintain infinity focus and accurate registration distance after extended use. Metabones publishes ongoing firmware updates to address compatibility with newly released lenses and bodies, reflecting an unusually long product support cycle for the adapter category. The result is a product line favored by independent filmmakers and hybrid shooters who depend on legacy or cross-system glass within current cinema and stills workflows.