This filter generates 2-5 stops of neutral density depending on how it is rotated.

In addition, the filter is indexed so you know exactly how many stops of neutral density you are getting. It screws on like any other filter and you dial in your filtration by just rotating the front element. No need to constantly change filters as the light changes, just dial in another grade of filtration.

Neutral Density Factors:
* ND.6 (exposure adjustment = 2 stops, reduces ISO by 1/4)
* ND.9 (exposure adjustment = 3 stops, reduces ISO by 1/8)
* ND1.2 (exposure adjustment = 4 stops, reduces ISO by 1/16)
* ND1.5 (exposure adjustment = 5 stops, reduces ISO by 1/32)