Canon EF to Canon EFR mount T Speed Booster ULTRA 0.71x (EOS R)

The Metabones Canon EF to Canon RF-mount T Speed Booster ULTRA 0.71x (EOS R) converts Canon EF lenses for use on RF-mount cameras, including the EOS R series, while increasing maximum aperture, widening field of view, and maintaining electronic and autofocus functionality. Its advanced optical design, robust construction, and assignable control wheel make it ideal for both photography and cinema work.

The Metabones Canon EF to RF-mount T Speed Booster ULTRA 0.71x (EOS R) is a professional-grade adapter that allows Canon EF lenses to be mounted on Canon RF-mount cameras, including EOS R series, EOS C70, and RED KOMODO 6K. By reducing the effective focal length and increasing the maximum aperture by one stop (up to f/0.9), it delivers brighter images, faster autofocus performance, and a wider field of view for exceptional creative flexibility.

The optical system features a 5-element/4-group design incorporating ultra-high index tantalum-based optical glass, providing enhanced MTF, reduced distortion, and minimal vignetting. This ensures sharper images across the entire frame, from center to corners.

Smart electronic integration supports dual-pixel autofocus (DPAF), video AF, image stabilization (IS) lenses, and full EXIF data transmission, including lens name, focal length, and aperture. The adapter also includes a multi-function control wheel for customizable functions such as ISO, shutter speed, aperture adjustment, or depth-of-field preview. For cinema users, it is compatible with Canon CN-E lenses and supports high-end video cameras like the EOS C70 and RED KOMODO.

Durability and precision are ensured with aluminum alloy and brass construction, chromium plating, and a satin black matte finish. The interior is flocked to reduce internal reflections, and a rubber gasket protects the RF-mount connection from dust and moisture. A detachable tripod foot compatible with Arca Swiss, Markins, and Photo Clam ball heads adds stability during extended shoots.

Key Features

Optical:

• Speed Booster ULTRA 0.71x magnification
• Increases maximum aperture by 1 stop (up to f/0.9)
• Enhances MTF for sharper detail
• Wider field of view (0.71x)
• Advanced 5-element/4-group tantalum-based optical glass

Electronic:

• Full autofocus support, optimized for shorter effective focal length and brighter aperture
• Dual-pixel autofocus (DPAF) and video AF support
• EXIF data transmission (lens name, focal length, aperture)
• Image stabilization (IS) lens support
• Built-in multi-function control wheel for ISO, shutter speed, aperture, or depth-of-field preview
• LED indicator shows communication status
• Powered by camera body (no external power needed for most lenses)
• Cinema camera support (Canon EOS C70, RED KOMODO/Komodo-X)

Mechanical / Build:

• Detachable tripod foot compatible with Arca Swiss, Markins, and Photo Clam
• Flocked interior to reduce reflections
• Rubber gasket for dust and moisture protection
• Aluminum alloy and brass construction with chromium plating
• Satin black matte finish