the Speed Booster ULTRA has a magnification of 0.71x, and so it effectively reduces the crop factor of mirrorless cameras with DX-sized sensors, such as Sony E-mount and Fuji X-mount cameras, from 1.5x to 1.07x. However, the new ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is well corrected for use with virtually all fullframe SLR lenses regardless of exit pupil distance. Thus, the Speed Booster ULTRA performs extremely well with professional-grade f/2.8 zoom lenses such as the 24-70mm f/2.8 and 70-200mm f/2.8 zooms by Canon and Nikon to produce 17-50mm f/2.0 and 50-142mm f/2.0 high-speed zooms, respectively. Similarly, high-speed fixed focal length lenses such as a 50mm f/1.2 will be transformed into a 35.5mm f/0.9 lens with excellent contrast and resolution from the center all the way to the edges of the image.

Key Features
Design for attaching full-frame PL Prime Lens to Canon RF-mount cameras/camcorders ;
Increase maximum aperture by 1 stop;
Increase MTF;
Makes lens 0.71x wider;
The advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA (patent granted);
Positive-lock PL lens mount;
Felt material flocked inside the opening to reduce internal reflection;
Satin Surface Finish;
Aluminum Alloy and Brass Construction with Chromium Plating;
Detachable Arca-Type tripod foot compatible with Arca Swiss, Markins, and Photo Clam ball heads(clamp directly or attach to quick release plate by a 1/4"-20 screw);
This product is designed for the APS-C format camera (eg. Canon EOS C70 and RED Komodo, etc.) or using with the APS-Crop mode of EOS R3, EOS R5, EOS R6, EOS R and EOS RP.

Camera Mount: Canon RF
Lens Mount: Arri PL
Magnification : 0.71x
Weight: 0,71 Kg