The Carl Zeiss T* Circular Polarizer 49mm filter from Zeiss helps reduce reflections and glare by filtering light that has been polarized due to reflection from non-metallic surfaces. A polarizer is capable of absorbing a significant amount of this polarized light, thereby enhancing the rich color saturation of skies and foliage, penetrating the haze distance, and minimizing reflections on glass and water.

A circular polarizer differs from a linear polarizer because it incorporates a quarter-wave plate within a linear polarizing filter. This addition aids in the circular polarization of the reflected light, allowing the camera's autofocus and auto exposure mechanisms to function properly.