Not too long ago I purchased a pack of neutral density filters after having been inspired by another article here on Photoblog. We're getting ready to go on vacation to the Upper Peninsula in Michigan and I know there will be plenty of opportunities to use the filters, and I want to see what they can do before we actually get there. These are a couple of photos taken at a nearby creek - the rapids aren't too big right now but you can get the general idea.
I used a ND 64 (6-stop) filter, with the ISO set at 100, the aperture at f/8, and the shutter at 15 seconds:
For this shot, I used a ND 1000 (10-stop) filter, with the ISO set at 100, the aperture at f/8 and the shutter set to BULB and kept it open for five minutes:
You can see the slight blur in the rapids, giving them a "dreamy" look.