Tiffen 138mm Mounted Warm Linear Polarizer Filter

The warming effect of this filter can be obtained under daylight when this filter is used on a film camera system with daylight film installed, or on a digital camera system with its daylight white balance setting selected. This filter's overall coloration reflects a mired shift value of +45.

A linear polarizer differs from a circular polarizer in that it does not contain an additional quarter wave plane. The addition of a quarter wave plane is to circularly polarize linearly polarized light for the use of auto focus and exposure functions. Due to how the light is broken down and filtered with a linear polarizer, in-camera auto focus and exposure accuracy become skewed during use. When the light becomes circularly polarized, it permits the use of these functions.

This filter is recommended when not using in-camera exposure metering or autofocus, is non-coated, and has approximately 40% average light transmission. Constructed from optical glass for clarity as well as color fidelity, it is mounted for use in third-party or custom filter holders. No front or rear threads are included on this filter's ring, or mount.