![Permalink to The latest Nikon patents: 400mm, 500mm and 600mm f/5.6 Phase Fresnel (PF) lenses](https://nikonrumors.com/wp-content/uploads/2018/02/Nikon-500mm-f5.6-lens-patent-144x144.jpg)
Nikon filed a patent (P2018-17857A) in Japan for a 400mm f/5.6 (22cm long), 500mm f/5.6 (28cm long) and 600mm f/5.6 (33cm long) full frame Phase Fresnel (PF) lenses. Addition information on Nikon Phase Fresnel (PF) lenses can be found here: Nikon’s Phase Fresnel (PF) lens explained As of today the Nikkor 300mm f/4E PF ED VR is the only […]