Honestly didn't expect much out of this filter, but it works great. Little distortion at certain points, but that is expected from a variable filter
03.01.2017
I haven't had a chance to actually use it yet, as I mostly use it for waterfalls. Everything is frozen or trickling now. Playing around with it though, showed that it should be very effective. You can see it's varying darkness as you rotate the ring.
29.12.2016
When I don't feel like assembling my filter squares and my holder, this is my got to filter. (Only when I am in a hurry)
13.12.2016
It's fun! It has a huge range so I only need one. The only flaw is I can't put it in my stack. The front is a larger diameter than the 67mm rear. Not suitable for all day use. Will need a separate lenscap.
17.06.2016
As much as I like K&F products, I cannot give 5 stars for this product. Maybe 3 would be too much also.The filter is similar to one I've built some time ago and it is made of 2 linear (not circular) polarizing filters. Even though the idea sounds good, there are inevitably two problems:1. (smaller problem): the filter will be a polarizer at all times, and so depending on the position it ends up in after being screwing in, it can be annoying. Rotating the camera will change which glare direction will be removed. This is not a huge problem, because if you want to reduce glare on the other direction, you can bring the filter to the same "blackness" but on the other side of the minimum (or maximum) point.2. (more serious problem): when at the maximum blocking point, the image is not uniform. There is not a position in which the filter acts like a regular 400ND, but a transition in which the image is blackened only in a certain area which moves while passing through that point. Maybe my english is not great, but you get the idea...In conclusion, if don't want to work at to the claimed 400 value and don't mind it acts like a polarizing filter at all times, it is OK.Needless to say, when you work with high values, you may want to focus the camera first and then block the light while keepting the focus.
12.10.2014