2 stars because the optical quality is very poor. I would add a caveat: the quality is good use in wide angle, however in long focal length, that is where it deteriorates very significantly (tested with my Nikkor 28-300 on a D600). Although it takes a minimum budget of 50 is known, and choose reputable references to hope to have a filter that does not degrade obviously the precision and sharpness of images. Here the Polaroid effect works, certainly, but the soft image price that lost the most basic dives. This optical degradation obviously finds whatever the filter setting. Having already used a filter Hoya Pro 1 for several years (but with a diameter that no longer corresponded to my goals), so I'm used to this type of filter. And I can judge so knowingly. However, previous reviews left me thinking I was going to find the same quality for much less. It is not, by far. However, for a beginner with some curiosity, or if we only pictures in wide angle, low investment allows to understand the interest (or not) of this filter, sentraîner and see in which case it is interesting or not, and then consider a more serious purchase. For a polarizing filter is not magic, and it takes some skill to learn to appreciate in advance the potential contribution that it will provide. However, a large special thank you contacted customer service via chat (Hela) for his kindness. Because I had ordered a first time this filter, then the command was terminated for lack of availability. But this product was available again after two days. And I was a bit miffed to have to order it again this time paying the postage, so it was a bulk order the first time, for which the postage was offered. The filter I finally sent without postage. A big thank you for this customer focus. I am disappointed the filter, but not always that Amazon achieves a high quality service addendum: I traded this filter against a pro1 Hoya certainly more expensive, but I can confirm that the optical quality of the latter is disproportionate
