Neutral Density filters are extremely useful in video and still photography applications when you want to control light and use lower shutter speeds. Check out Blackstone filters at http://www.winecountry.camera/ You can get 15% off of anything in the store by using offer code AOP on checkout. Typically in video you will get the best motion estimation by using a 180 degree shutter. This is double the frame-rate of your video clip. In still photography and landscapes you want to be able to capture motion of things like clouds or water for a dramatic effect. All ND filters are not created equal. Color casts are a huge problem as are distortions from glass inconsistencies. I use only Blackstone filters for this reason. Music is from Epidemic Sound. If you need music for your videos, Epidemic is simply the best in the business. Check them out here: https://goo.gl/v5wWKr