DIY Variable ND filter from DvRebellion.com on Vimeo.
A Neutral Density (ND) filter is a very useful accessory to have for your DSLR when you want to use a slow shutter speed on a bright day. When there is lots of light, your camera will use a fast shutter speed which will freeze action. But if you want to picture motion with a slow shutter speed, you need a way to cut down on all that light, and the simplest way is to use an ND filter. This video shows you how to make a variable ND filter.