Circular ND filters provide continuously variable, linear attenuation of light intensity by rotating the filter around its center. Transmitted intensity varies as a function of the optical density range. The filter can be used for natural light and also for laser applications. By using two filters in combination in reverse rotation can obtain a fixed density attenuation and extends the number applications. Sizes are available from 25 mm to 100 mm in diameter.

Main features

■ Wide operational wavelength range (250-2500 nm with UVFS substrate)

■ Maintains the transmitted spectral profile