Metabones has announced the Canon EF-RF mount T Speed Booster ULTRA 0.71x, price tag $479, which is designed to reduced the 4K crop factor from Canon EOS R cameras.
Metabones says the Canon EF-RF mount T Speed Booster ULTRA 0.71x will mitigate most of the 4K video crop factor from the EOS R (1.75x) and EOS RP (1.63x), reducing it to 1.24x and 1.15x respectively.
The Canon EF-RF mount T Speed Booster ULTRA 0.71x will adapt a Canon EF lens to the EOS R series RF mount and effectively makes the lens 0.71x wider.
The Canon EOS R Speed Booster increases maximum aperture by a stop, and it supports Dual Pixel AF and video AF. Other features include:
Optical
- Increase maximum aperture by 1 stop. (with a maximum output aperture of f/0.9).
- Increase MTF (details).
- Makes lens 0.71x wider.
- Advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA (patent granted).
Electronic
- Autofocus. AF speed is properly adjusted to account for and leverage the shorter focal length and the brighter maximum aperture.
- Dual-pixel autofocus (DPAF) and video AF support.
- Focal length and aperture are adjusted in EXIF (see note 3).
- Image stabilization (IS) lens support.
- Store EXIF data (lens name, focal length and maximum/minimum aperture) for one manual lens in the adapter.
- Build-in multi-function Control Wheel (turn/ push-in) for assignable functions(eg. ISO, shutter speed or aperture control, depth-of-field preview).
- LED indicator shows communication status.
- Powered by camera body. With most lenses, no external power source required.
Mechanical
- The tripod foot is detachable and compatible with Arca Swiss, Markins and Photo Clam ball heads.
- Flocking to reduce internal reflection.
- Rubber gasket protects the RF mount connection from dust and moisture.
- Aluminum alloy and brass construction with chromium plating.
- Satin surface finish.
Via Canon Watch