...far from perfect, at least the copy I got. While it looks transparent to the naked eye, I have experienced ghosting when shooting strong light sources, like the built-in flash in the mirror for example. I never screw my filters very tight, so I can unscrew them easily later and it won't damage my lens' auto focus mechanism - this filter got stuck once on one of my lenses, I had to apply lots of force to unscrew it, something that could have cost me the lens and didn't happen with cheaper filters, so it is not the lens thread. It's been paper weight since this incident. This is my first and last Sigma product I buy.