Tiffen 4x5.65 Clear Filter

Tiffen 45650CLR (45650-CLR) 4x5.65 inch Clear Standard Coated Filter tiffen_45650clr / 45650CLR. Tiffen Optical Filters 
Tiffen filters are manufactured using ColourCoreâ„¢ technology, a closely guarded proprietary process that entails permanently laminating the filter material in between two pieces of optical glass that are ground flat to tolerances of a ten-thousandth of an inch, then mounting them in precision metal rings. The ColourCore process allows us to control the colour and density of Tiffen filters, and the characteristics of special effects filters with much greater accuracy than typical dyed-in-the-mass filters, which usually exhibit colour and density . 
When Tiffen filters are ground and polished, the Colourcore is unaffected, so colour and density remain uniform. Indeed, when you hold a group of Tiffen filters of the same type against a white sheet of paper, they all look identical -- because they are! Try this with our competitor's filters and you're likely to see slight variations. 
Maybe that's why most top Hollywood motion picture studios rely on...