The New Speedboosters by Metabones for Blackmagic

The original Metabones Speedboosters are available in several versions adapting various full-frame lenses to NEX, micro 4/3, and Fuji-X cameras. They offer a magnification factor of 0.71X; meaning the lens focal length changes by this factor and the aperture increases by one stop. For example, a 100mm f/2.8 full-frame lens becomes a 71mm f/2.0 lens when mounted on an NEX camera by a Speedbooster.

For people shooting video on micro 4/3 and APS-C size sensors, the Speedboosters give them an opportunity to shoot with full-frame lenses and reduce the ‘crop factor’ associated with shooting on the smaller sensor size. The also increase the aperture of the lens, letting in more light.

Check out the full review here: PetaPixel