Since the arrival of the RF mount, Canon has shown that they are willing to push the boundaries of lens design to the next level. It doesn’t seem like they plan to slow down, with two new patents emerging, including one for a 300mm f/2.3 mirror lens with autofocus.
Mirrorless lenses gained some popularity a few decades ago by providing an affordable solution for photographers to enjoy super telephoto focal lengths in a relatively small package. . They work by using mirrors inside the lens to allow a longer focal length by bending light rays back to themselves several times before they are sent to the sensor. Typically, these lenses are designed to focus manually with a slow aperture, usually 500mm f/8. Another drawback is that due to the mirror in the center of the lens, out-of-focus elements have a very distinct ring shape, which can be distracting.
Canon’s new patented lenses, on the other hand, overcome narrow apertures and manual focus trends, as both feature autofocus, with a 300mm f/2.3 design and The other is the 400mm f/5 design. The 300mm option is particularly eye-catching, as even professional 300mm lenses often max out at f/2.8. There is still a second mirror in the center of the optical path, meaning such a lens will still have a ring-shaped bokeh effect, but it is quite interesting to see such designs appear.
Of course, just because a patent is filed doesn’t mean the product will hit the market, but it’s nice to see Canon experimenting both ways.
