filters

     
The 10 stop is an extremely dark filter that blocks of almost all the light entering your camera which can be really useful for landscape photography because it lets you slow down your shutter speed to great lengths. This allows you to make smooth and ghostly water. 

A 3 stop ND filter is the less extreme version of the 10 stop. The 3 stop lets you increase contrast in the picture and slow down your exposure by 3 stops of light. This will allow you to get somewhat silky water in mid day. When the sun sets the filter will give you the same effect that you have with the 10 stop in the day. This is the average low priced ND filter.
     
Circular polarizing filters reduce haze in your photos increasing color saturation and giving you clear reflections off of wet and metallic surfaces, giving plants and rocks increased clarity and color saturation, and letting you see under the surface of lakes and streams.