I can only comment to my knowledge. I am ambitious amateur photographer and am currently doing my first steps when it comes to long-term exposure. With the filter, I was happy. There was no color cast in the photo, as it is known from cheap gray filters. I have made with them nice shots at the sea. The only thing I have to complain about is that the filter is very difficult to screw on the lens and therefore hard to come back down, because the thread often jammed. I do not know if it was only because of my copy, or if it is fitted as standard so. All in all, the filter is a good value for money!