Formatt BF 77-CP2000RH 77mm HD Circular Polarizer Filter

Formatt BF 77-CP2000RH 77mm HD Circular Polarizer Filter produces the same effect as a linear polarizer, deepening skies and minimizes reflections, but is used in cameras where polarizing elements are used in the beam-splitters of the camera. If using a linear polarizer
If you use a linear polarizer filter with such cameras, the light can become cross polarized (giving the same effect as using two polarizers together). Circular polarizers are made from a different polarizing material than linear and will usually prevent the cross polarization.