I bought this filter to allow me to do the portrait outdoors when no possibility not to get in the shade and I need a large aperture to reduce the depth of field for hide an unsightly background example (I know, I accumulate difficulties)
result of the first test when I have darkened a little bit, GROSSE loss stung either on board as the center for the portrait that is not worth .... I not recognize my goal
I have not tested long exposures, but I do not do too much idea about the result.
For troubleshooting or video it must do the job for the rest "you get what you paid for" neither more nor less