Add movement / Slow down your exposure with an ND filter
1 Blur it out
Once you have a few stills from your basic setup, liven up the scene with a longer shutter speed to blur moving elements, such as water and clouds. To do this you’ll need a neutral density filter, which darkens your whole frame. Here a 10-stop filter gave us a 20-sec exposure.
2 Calculate your exposure
It’s possible to use exposure calculators or charts to determine the difference in shutter speed to give a balanced exposure. But in Manual mode it’s just as easy to click down the shutter speed by 10 stops on the camera and take some test shots to review as you go.
3 All in the timing
It’s all well and good throwing an ND filter on and expecting good results, but you have to remember that only moving things will be blurred in the final shot. Wait for clouds to seep into the frame before taking your photo for maximum interest in the bottom and top of the frame.