Template:POTD/2014-05-18
A neutral density filter is a filter that reduces or modifies the intensity of all wavelengths or colors of light equally, giving no changes in hue of color rendition. The filter reduces the amount of light entering the lens, allowing the photographer to select combinations of aperture, exposure time and sensor sensitivity to avoid overexposed pictures. It would normally be attached to the lens, but is hand-held here to illustrate the effect.Photograph: Robert Emperley