Canon has been pushing ahead with vigor in the full frame mirrorless market, releasing a wide variety of competitive cameras and innovative lenses. The company shows no signs of stopping, as patents for more high-level lenses have appeared.
The patents detail specifications for three lenses: the RF 200mm f/2L IS USM, RF 300mm f/2.8L IS USM, and RF 500mm f/4L IS USM. All three of these lenses had direct counterparts in the EF lineup and were popular among sports and wildlife photographers who needed the combination of a lot of reach and a fast aperture all in a rugged package that offered high image quality, fast and accurate autofocus performance, and good image stabilization.
Beyond that, the EF 200mm f/2L IS USM found an unexpected second home among portrait photographers as a lens that could couple superbly thin depth of field with high levels of telephoto compression, creating images in which the subject practically popped off the screen. Of course, just because patents are filed does not mean the respective products will appear on the market, but I would be extraordinarily surprised if we do not see these lenses eventually, as they are widely used tools in sports, bird, and wildlife photography and would, without a doubt, be quite popular. Given that the 200mm f/2 is reserved mostly for indoor sports due to its shorter focal length, I suspect we’ll see the 300mm f/2.8 and 500mm f/4 first.