Nikon are working on a compact 500mm super telephoto

The AF-S NIKKOR 500mm f/5.6E PF ED VR will be a high-performance super-telephoto lens that promises to be significantly smaller and lighter than comparable lenses due to the adoption of a Phase Fresnel (PF) lens element. 

The PF element is the same as used in the AF-S NIKKOR 300mm f/4E PF ED VR, which became the world’s lightest full-frame autofocusing 300mm lens when it was announced. Nikon says the portability of the new 500mm lens will allow it to be used in a wider variety of situations, and for capturing fast-moving and unpredictable subjects, making it a solid choice for sport and wildlife photography.

PF (Phase Fresnel) Lens Elements

The PF (Phase Fresnel) lens effectively compensates chromatic aberration utilising the photo diffraction phenomenon*. It provides superior chromatic aberration compensation performance when combined with a normal glass lens. Compared to many general camera lenses that employ an optical system using the photorefractive phenomenon, a remarkably compact and lightweight body can be attained with less number of lens elements.

*Light has characteristics as a waveform. When a waveform faces an obstacle, it attempts to go around and behind it, and this characteristic is referred to as diffraction. Diffraction causes chromatic dispersion in the reverse order of refraction.

Details, including the release date, images and suggested retail price will be shared soon.