A little over a year ago I wrote a post about the Viltrox Focal Reducer for EF lenses on EF-M bodies that supported full AF and camera connectivity, a 1 stop speed boost, as well as EXIF data modification for focal length and lens speed. I even did a video on it video link here. That was a solid device, well made, and optically very good. I also admonished Metabones for not having such a device at all. Metabones is the company that really brought this tech to the still photography market. They have a massive catalog of the craziest adapters you can imagine yet did not have the relatively easy Canon EF to EF-M speed booster. I say relatively easy because they already had one for EF to Sony E mount which has the same physical mount size and back focus. The electronics to convert EXIF data was present they just had to create proper electronic connection for Canon.
Well things have changed, and Metabones introduced a speed booster to mount full frame EF mount lenses on an EF-M mount camera with a full stop of speed and the full EXIF conversion recently along with a version for Canon R mount cameras. Metabones is the premier manufacturer for this type of device. They are are engineered in Canada and contract with Caldwell Optical in the USA to create the best speed boost focal reducers on the planet.
Next show June 27th in San Rafael, see all shows for 2020 here.