Quote Originally Posted by Bruce (Camclicker)
Nick, You sure about that?

I believe a "Factor" of 2 would be 1.4 stops and a factor of 1 would be 1 stop. I don't know about Hoya but I have a little booklet from B+W that says their ND Filters:

Filter
101 2X factor = 1 Stop
Simple way to deal with filters is to divide the film speed by the factor. A factor of 1 would mean no change. UV filters have a filter factor of 1.