Perfecting Your Light ®


Circular Variable Neutral Density Filters



The Circular Variable Neutral Density filter (UV-VIS-IR) is a filter wheel to linearly attenuate light as the filter is rotated. This technology is best used in high quality optical systems to change the intensity of light from 100% to less than 0.1%. As the filter rotates, the beam intensity is customized due to the density variation of a gradient metallic coating around the filter. Used from UV to the far infrared, density neutrality can be achieved for narrow band applications such as lasers, to wide band applications, such as the spectrum of white light. 

These filters are fully customizable in optical density gradient function, transmission gradient function, substrate type, coating materials, and size to meet customer requirements. Gradient function can be supplied from 45 to 360 of rotation and substrates can be supplied from 1.0” (~25mm) to 8” (~200mm) in diameter. Densities can be supplied as a standard linear or a customized gradient function. Custom quotes are available upon request.