If you're unfamiliar with ND filters, or just need a few tips on how to get great sunset images with your 10-stop ND filter, Chris Gin describes and illustrates his experiences. His article also describes how you can calculate your shutter speed, or if you're feeling lucky, just try a few test shots as he did.
Chris Gin writes:
Firstly for those of you who aren’t familiar with this type of filter, it’s basically a very strong neutral density (ND) filter which reduces the amount of light hitting the camera’s sensor by about 1000 times. ND filters are very common but they are typically only 3-stops in strength (reducing the amount of light by 8 times) so a 10-stop one is quite extreme.