Metabones Speed Booster

As camera formats proliferate, photographers seek ways to adapt lenses from their various systems to their other cameras. The Metabones Speed Booster, jointly developed by Metabones and Caldwell Photographic, creates not only an adapter mount between an APS-C mirrorless camera and full-frame DSLR lens but also increases the maximum aperture by a full stop and multiplies focal length by 0.71X, plus increases MTF. For example, an 85mm f/1.2 lens becomes a 59mm f/0.9 lens on an APS-C mirrorless model; combining the two factors makes the focal length multiplier approximately 1.09X. The first such adapter is for Canon EF lenses and Sony NEX bodies; other adapters for various lens/bodies combinations are promised in the future.