After trying a lot less expensive filter (reference Polaroid sold on Amazon) I returned it which was a big disappointment despite the rather laudatory comments. It was ok only the wide angle end of my Nikkor 28-300 mounted on my D600. However as soon as we left the wide angle, the softness of the images became perfectly obvious, and even unsustainable in the longest focal length. The polarizing effect obviously posed no problem, but it is the deterioration in the sharpness of the image that was the weak point, as with all cheap filters (unfortunately). So I immediately swapped and redo the same preliminary tests (a big thank you to Amazon for its customer focus) against the Hoya Pro 1D. Not surprisingly, the optical degradation is considerably lower. I do not say it does not exist to my the longest focal length (300 mm), but is extremely low. There are certainly better, but at what cost! I agree with the general opinion about the value for money of this product. And as mentioned several times in the comments, I mention my turn hard to screw and unscrew the filter above. Once screwed onto the lens, even without squeezing, it is difficult for me to unscrew it. I dare not think about my future land uses, during which we rarely any ease in handling the equipment. The polarizing effect is in line with what can be expected of polarizing filters. A master to good use.
