Nikon filed patent 201293548 in Japan for a Nikon 100-300mm f/4 full frame lens:
- Patent release date: May 17th, 2012
- Patent filing date: October 27th, 2010
- Focal length: 102 – 294mm
- Aperture: 4.1
- Angle of view: 8.2 – 24.1 deg
- Lens length: 282.43mm
- Image height: 21.6mm
- Lens design: 22 elements in 16 groups, 4 ED elements
FYI: few months ago Sigma discontinued their 100-300mm f/4 EX DG APO HSM lens.