Svbony UV/IR block filter (2")

The function of the Svbony UV/IR Block Filter (2") is to exclude unfocused infrared (IR) and ultraviolet (UV) light rays from imaging. Unlike the human eye - both CCD and CMOS system cameras are sensitive to these wavelength ranges, but lens systems cannot image them with visible light rays in the same focal plane. As a result, they create a disturbing halo (light fog) in the images as a lifeless spot.

This optical defect is not exclusive to the use of telescopes with lenses. With mirror systems, if focus extenders or coma correctors using lenses are placed in the light path between the tube and the camera, a UV/IR block filter may also be required.

Cameras with a built-in UV/IR block filter are not required for these models.