(Hinton, WV Railroad Depot) As a photographer, there are all kinds of tools at your disposal, from lenses and filters to lighting equipment and more. The neutral density filter is one of the more under-utilized tools, but I'd argue that it is one of the most useful pieces of equipment you could have. Why use an ND filter? The simple answer is that this filter lets you take long exposures in bright lighting. In other words, if you're standing on a sunlit beach, and you want the water to have that smooth effect that you can only get at dusk or dawn, then you'd need a 10-stop filter to help you...