Variable ND, Kenko or Hoya?
What do you need the variable filter for? The variable ND filters are not the best idea concerning their use in photography. They are mostly for filming. Even an average quality normal filter will give you better results than a high quality variable filter (and neither Kenko nor Hoya variable filters belong to this class).
|Nowhere by Nanard 92|
from The Illusion of Depth and Distance
|Green Tomato by lim yau tong|
from Growing Fruit