Tiffen 138mm WW IR Polarizer Filter

Description

The Tiffen 138mm WW IR Polariser Filter is a combination linear polariser and near-infrared to infrared control filter that is designed for digital cinematography. When this filter is used, it helps to reduce reflections and glare by filtering out light that has become polarised due to reflection from a non-metallic surface. Simultaneously, near-infrared light waves beginning at 680nm are blocked by approximately 80% and infrared light waves at higher frequencies are further impeded until nearly flat attenuation is achieved at 720nm.

This filter is useful as many digital motion-picture cameras are designed to maximise their ability to capture red hues, and in that process near-infrared or infrared contamination may occur. If the proportion of near-infrared or infrared light that reaches the sensor of a digital cinematography camera becomes too great, the results can show unwanted colour shifts, particularly in dark areas of the frame such as shadows where the appearance of black is dominant.

While helping to preserve colour accuracy when using a digital motion-picture camera, the Tiffen 138mm WW IR Polariser Filter also addresses the effect of light from the sun becoming partially polarised due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A polarising filter arranges, and filters, this directionally polarised light perpendicularly to the reflected light, allowing for the absorption of much of this light. This results in a noticeable reduction of glare and reflections from non-metallic surfaces and an increase in the saturation of skies and foliage.

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

This filter is recommended when not using in-camera exposure metering or autofocus. It is non-coated with a 3x filter factor that results in a 1.6 stop exposure reduction. Constructed from Water White optical glass, the Tiffen 138mm WW IR Polariser Filter is 138mm in diameter and mounted for use in third-party or custom filter holders. It is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass, grinding flat to a tolerance of 1/10,000th of an inch, and then mounting to precision metal rings. No front or rear threads are included on this filter's ring, or mount.

Features

• Mounted without front or rear threads for use in third-party or custom filter holders for film and television cameras
• Designed for use with CCD or CMOS sensors to filter out near-infrared and infrared light pollution that cause colour shifts frequently associated with high-definition recording while helping to reduce reflections and glare by filtering out light that has become polarised due to reflection from a non-metallic surface
• Blocks near-infrared light waves beginning at 680nm by approximately 80% until nearly flat infrared attenuation is achieved at 720nm
• Clears up haze in distant landscapes and provides more saturated, vivid colours
• Strongest polarising effect when used at a 90° angle from the sun
• Recommended when not using in-camera exposure metering or autofocus
• Non-coated
• 3.0x filter factor reduces exposure by 1.6 stops
• Constructed from Water White glass for increased optical clarity
• Filter Pouch for storage and transport

Specifications