The Nf - Gfx Expander 1.26x allows Nikon F mount lenses to be mounted on Fujifilm Gfx camera bodies without getting dark and / or soft corners. The magnification factor of 1.26x perfectly matches the image circle of the full-frame Nikon lenses to the medium-format sensor of the Gfx series cameras, and therefore the diagonal Fov remains exactly the same.The optical design consists of 5 elements in 3 groups, incorporating ultra-high index Lanthanum-based optical glass as well as one element made of fused silica, resulting in extremely good performances with professional-grade f/2.8 zoom lenses. For example, a 24-70mm f/2.8 lens becomes a 30-88mm f/3.5 zoom, and a 70-200mm f/2.8 lens becomes an 88-252mm f/3.5 zoomHigh-speed fixed focal length lenses such as the 50mm f/1.4 will be transformed into a very fast standard lens 63mm f/1.8 for the Gfx system..