Patent: Tamron 300mm f/2.8, 400mm f/4, 500mm f/4

It looks like Tamron may be entering the world of fast supertelephoto lenses. Three different optical formulas have appeared in the same patent application from Tamron. Embodiment 1: 300mm F/2.8 Focal length: 304.799 mm F No.: 2.8 Read more...