Variable ND filter

[Xanda73]

Anybody used one of these:

http://www.7dayshop.com/catalog/pro...d=111258&PHPSESSID=fp4k7gjipnot6ip3c9ji9598q1

Is there any point having a variable ND filter, or would it be used fully dark all the time?

 

[Tigger]

Can't view it mate - asks for login details

 

[Xanda73]

Similar item here, though more expensive:

http://www.singh-ray.com/varind.html