Faultless! Faultless! Faultless! I took a chance, after reading a great review online, about the Tiffen Filter. Normally, I'm using Hoya. But this has been fantastic. It also, comes with a 10yr warranty! I've recently been to the Lake District with my D600. With the Tiffen on my 16-35mm F4, I could with comfort at F8 ISO 320, get a lovely 30 second exposure, in normal daylight. You really can get some lovely effects with it. 100% on par with Hoya Pro1 ND64.