Landscape photographers and those that want to overpower a flash are bound to look to ND filters. ND filters cut down lots of excessive light so that you can shoot at a slower shutter speed when photographing landscapes–but they also do more than that. When strobists use them, they use them to cut down on the effects of ambient light and to give the image a look similar to that of a strobe overpowering the sun. In effect though, it also cuts down how much strobe is in the image, so its power output needs to be congruently to how much light the ND is cutting down.
So if you’re wondering how an ND Filter affects your image, hit the jump.