Canon Patent Application: Speedbooster adapter for EOS-M

We found a patent last week that gave us our first indications that Canon may be looking at speed-boosters for the EOS-M, and this week, we now have some definite proof.

This patent application is for a converter that takes a EF lens (long registration distance lens) and reduces the focal length and decreases the aperture at the same time.

The example they give is ta 51.46mm F1.45 lens with an image height of full frame, and a 39.80 back focus (an EF full frame lens) and converts that to a 40mm F1.19 with an image height of 13.66 (APS-C) with a 18mm back focus (EOS-M APS-C)

Where the previous patent we found specifically mentions that it's not a patent in regards to the converter lens itself, this patent application is specifically containing a canon focal reducer (speedbooster) lens.

What good is a speedbooster or focal reducer lens.  it changes the angle of view of a lens so that when you put a full frame lens on a crop camera body, the camera angle of view is similar to the angle of view that the lens had on a full frame camera body.

Of course with all the patent applications, this is something Canon is researching, and may never reach our hands as a finished product.

Japant Patent Application 2018-189864