As regards the top quality of this filter I can agree with the previous reviews only and therefore do not go again prepared to B + W speak for themselves. I have the filter with the F-Pro version (not Slim) ordered so that the lens cap securely holds. And now the most important thing, the vignetting. On my Canon 5D MK II with the 24-105 L IS USM comes with this filter to no (additional) vignetting. Owner of this combination can rely on these filters and save the extra for the Slim version, also keeps the original lens cap bombproof.