Low Pass Filter pack
The low pass filter pack is situated in front of the sensor and contains an optical low pass filter, an infrared (IR) cut-off filter and an ultraviolet (UV) cut-off filter.
Optical Low Pass Filter
The low pass filter blocks high image frequencies that would lead to artifacts when captured by the sensor. It is made from a modern, high performance crystal with optical properties that have been fine-tuned for a perfect match between the transmitted image content, the sensor's photosite structure and the down-sampling algorithm in the camera. The result is the creation of super sharp yet natural HD, 2K, 4K UHD or 4K Cine images.
IR and UV filters
The IR and UV cut-off filters let only those light frequencies reach the sensor which can be converted into a meaningful image. They were both specifically designed for the spectral response of the camera's sensor.