Photography is an art. You should know how to wield a camera and use it effectively to create the effect that you want in your photograph. Running stream or waterfalls make for excellent background but would not create the effect if they are not photographed properly. If you want to create a soft look for water and show its smooth flow then you should use a setting with a slow shutter speed.
The best way is to set the aperture and shutter speed manually for the best results. Water would have a blurrier look with the slower shutter speed. Thus the water would acquire a milky look. Check out more shutter speeds and experiment with various shutter speeds to choose the right one of the lot. Use tripod when you are using slow shutter speeds. You can find out more about photography and tips on it from various sites on the internet. One such site is www.phototips.com.
The best way is to set the aperture and shutter speed manually for the best results. Water would have a blurrier look with the slower shutter speed. Thus the water would acquire a milky look. Check out more shutter speeds and experiment with various shutter speeds to choose the right one of the lot. Use tripod when you are using slow shutter speeds. You can find out more about photography and tips on it from various sites on the internet. One such site is www.phototips.com.