Haida NanoPro ND Filter (82mm, 7-Stop)

I have used many 10 stop ND's in the past and settled on a but was never really thrilled with it. There was always something about the images that bugged me. I decided to test it , alone and then in front of a polarizer , each time I noticed a pretty noticeable drop in sharpness, especially fine detail smearing. Considering the cost of it this shouldn't be happening. So I searched for a new one and found an intense review of 10 stop ND's and the Haida Nanopro MC ND 10 stop was part of it. It came out on top along side one other, but with the price of this filter it was a no brainer to buy and test out. I ordered it from and tested it right away. Straight Image, Image with the ND, and Image with both the ND and a Nikon Circular polarizer behind the ND. NO difference in sharpness, ZERO. You wouldn't be able to tell the difference between the 3 , even at 100% zoom and beyond. I tested it on Modern AI lenses, and Vintage Nikkor S and H lenses with single coatings all tested with the same result. No color cast either. I went out with the Haida ND and the Nikon Polarizer and shot outside, long exposure with foliage and water. Same result. Sharp sharp sharp. All on a D810 in Bulb/Mirror up. Haida has just won a customer for life.