I love flowing water. Images of flowing water speak to me more than any other landscape photograph except perhaps for sunsets. There is something both dynamic and serene about water flowing gently down a stream or the surf crashing against the rocks. Water just speaks to me.
To get that smooth flowing look when photographing running water, I’ve found that a shutter speed of about 1 second is usually required.
Singh-Ray’s Vari-ND neutral density filter allows me to control the amount of light which passes through my lens from 2 to 8 stops of exposure. With the filter mounted on my lens and set to its lowest setting (minimum density) I can frame my subject (the rocks and flowing water) and use my camera’s auto focus system without any trouble. When I’m ready to shoot, all I need to do is turn the outer ring to increase the density until my long shutter speed provides the effect I’m looking for in the running water. I could achieve the same effect using a conventional neutral density filter but it’s a much more time consuming process.