Neutral Density filters (ND filters) evenly attenuate transmission, reducing the intensity of light by reflecting or absorbing a portion of it, giving no changes in hue of color rendition. The optical properties of the filter mainly depends on the Optical Density (OD) of the filter, i.e. the negative of the common logarithm of the transmission coefficient. The most common applications of Neutral Density (ND) filters lies in the field of photography, because they can reduce the amount of light entering the camera lenses, photographers are given more freedom to adjust appropriate aperture size, shutter speed, exposure time to obtain the desired depth of field which would be impossible to acquire without Neutral Density (ND) filters. Other applications of Neutral Density (ND) filters include imaging or laser applications where over exposure of light are harmful to camera sensors or other optical components, or when excessive light will cause inaccurate results in photometer applications.
Hangzhou Shalom EO offers a wide variety of Neutral density Filters for Ultraviolet (UV) (250-380nm), visible spectra (400-700nm), or Visible and Near Infrared (V&NIR) (400-1100nm), Infrared (IR) (2200-15000nm) applications. Continuously variable ND filters in rectangular or round shapes are also available. The substrate materials could be BK7, colored filtering glass, UV fused Silica or Silicon and Germanium, together with stocks and custom modules optional.