Tokina Cinema Formatt Hitech 138mm Clear Optical Flat Filter Universal Wall Mount Bracket a proud member of Sigma's a proud member of Sigma's acclaimed Art series 5 Lens (EF Mount) stands out in the realm of cinematography for its affordability and high performance The Tokina Cinema Formatt Hitech 138mm Clear Optical Flat Filter is one of the most affordable and essential pieces of kit for any cinematographer looking to protect their investment in lenses by protecting the lens from challenging shooting environments this Schott B270 super white optical glass is capable of matching the highest resolution cameras on the market today and can provide invaluable protection when using jibs