Recently I bought a variable ND filter for my Fujifilm XF14mm (21mm equivalent in full frame camera) f/2.8R wide angle lens. I bought the Phottix VND Variable ND filter. Today I tried it out for the first time.
There were almost no movement in the water at all, I was hoping for a little bit more movement to blur everything out. Here I am at f/16, 20 second exposure at ISO 200 - the lowest ISO on the Fujifilm X-Pro1.
I am very happy with it. I could have gone to f/22 and gotten a even longer shutter time and maybe blurring the the water even more. But.. the sea was so calm today. Anyway, the filter itself did its job, I adjusted it to full effect, meaning 8 stops slower shutter time. You can adjust it from 2 to 8 stops. Nice!
Here's another shot, after a boat had passed by making some waves:
Fujfilm X-Pro1 + XF14mm f/2.8R, Phottix VND Variable ND filter, ISO 800, f/11, 1.7sec.