Polarizer Filter: in order to avoid the image of reflection that is not in want, use a polarizing filter. play with the filter, the light will be filtered so that maasuk avoid direct reflection and the colors brighter.
UV filter: in the mountains and the sea of UV rays are stronger than in the plains, this raises a picture with fog effects. filter or UV filter Skyline can reduce this effect.
Gradual ND filters: a strong contrast, as in the photo Landscape, can be in a balance with the Gradual ND filter.