WHAT IT DOES Wonder how photographers get flowing water to look like a stream of fog? They use a strong Neutral Density (ND for short). The easiest explanation for what an ND filter does is reduce the amount of light entering your camera by set amounts. ND filters are dark with no color to them at all, hence the “Neutral” name. The filter can be used in a variety of situations to create effects that are simply not possible to get any other way. THE TWO MAIN USES OF NEUTRAL DENSITY FILTERS ARE: The best way to get these dreamy blurred motion effects is to use a strong neutral density filter like the Hoya SOLAS IRND 3.0. This dark filter reduces the amount of light entering the lens by a full 10 stops. In real world terms that means if on a sunny day the camera shows an exposure of 1/250 of a second shutter speed and an F/8 aperture, the IRND 3.0 will reduce the shutter speed 10 stops so with the same F/8 aperture the shutter speed would be 2 full seconds! In darker situations, such as a stream in a forest on a cloudy day, shutter speeds as slow as 30 seconds can be obtained! Always use a tripod when using strong ND filters to get long exposures so only the motion is blurred, not the things that are not moving! Some will say that you can always stop down to a very small aperture such as F/16 or F/22 but keep in mind that most lenses will not be as sharp due to refraction issues at these small apertures. So unless you need the depth of field for an effect, apertures smaller than F/11 are not recommended for most lenses. ALLOW WIDER APERTURES TO BE USED