138mm Round T1/2 IR Filter is a near-infrared to infrared control filter that is designed for digital cinematography. Many digital motion-picture cameras are designed to maximize 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 color shifts, particularly in dark areas of the frame such as shadows where the appearance of black is dominant.
When the T1/2 IR Filter is used, near-infrared light waves beginning at 680nm are blocked by approximately 45%. Infrared light waves at higher frequencies are further impeded until nearly flat attenuation is achieved at 775 to 800nm. This process helps to ensure that the light that falls on the camera's sensor is limited to the visible spectrum. Potential near-infrared or infrared color shifts are prevented or minimized, which preserves color accuracy throughout the frame. While a Tiffen T1/2 IR Filter is sufficient for many cameras, others may have sensors that require a higher degree of near-infrared and infrared control, such as that provided by a Tiffen T1 IR Filter.
This filter is constructed from Water White glass for increased clarity as well as color fidelity. 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. It measures 138mm in diameter and is suitable for use in select matte boxes and sunshades.
Features & Benefits
- Designed for use with CCD or CMOS sensors to filter out near-infrared and infrared light pollution that cause color shifts frequently associated with high-definition recording
- Blocks near-infrared light waves beginning at 680nm by approximately 45% until nearly flat infrared attenuation is achieved at 775 to 800nm
- Constructed from Water White glass for increased optical clarity
- No dichroic coatings to further ensure color accuracy
- 1.41x filter factor reduces exposure by 0.5 stops
- Measures 138mm in diameter and is suited for use with select matte boxes and sunshades
