The Speed Booster ULTRA features the latest evolution of optics from Caldwell Photographic USA and is available for E-Mount and Fuji X-mount cameras (to cover APS-C or Super 35mm recording areas). The new glass brings with it an increase in performance – sharper corners and better contrast. The increase in performance over the original Speed Booster is made possible by the use of cutting edge high index tantalum glass, in 5 elements in 4 groups;…