Tiffen 4x5.65" Linear Polarizer Filter

The Tiffen 4x5.65 linear polarizer cuts reflections and glare from non-metallic surfaces and deepens skies, for a cinema matte box. It is used on car windscreens, water, glass and foliage, where a reflection would otherwise hide what is behind it.

Rotate the filter in the matte box tray while watching the monitor, and the reflection fades to a minimum at the right angle. Skies go darker and blue, and foliage looks more saturated, because the filter removes surface sheen. Expect to lose about 1.3 stops. Because it is a linear polariser, it can interfere with in-camera autofocus and exposure metering, so use it with manual focus and an external meter or waveform.

The filter is 4x5.65 inch (Panavision size), made with Tiffen's ColorCore process, with the polarising film laminated between two pieces of optical glass ground flat. The filter factor is 2.5x, a light loss of 1.3 stops, with around 40% average transmission. It drops into a standard 4x5.65 matte box tray with a rotating holder.