I bought this filter for my Canon 2.8 / 70-200 IS II and unfortunately had to notice a decline in image quality. I've done several tests without filters, with a Hoya and this Canon. With the Canon filter I had a slight back focus and image quality (sharpness) was not as good as without a filter or the Hoya. Vignette I can not find the filter and mechanically fits blameless. I'm going to try again with Rodenstock.